Sample records for anterior hip impingement

Apophyseal injuries of the pelvis have increased recently with increased participation of teenagers in contact sports. Apophyseal fractures of the pelvis should be ruled out from apophysitis, os acetabuli and bony tumors. We report a case of fracture of anterior-inferior iliac spine following indirect injury to the hip in a young football player. The patient failed to get better with nonoperative management and continued to have pain in the left hip and signs and symptoms of impingement. He improved following surgical excision of the heterotopic bone and did not have any evidence of recurrence at 2 years follow- up. PMID:27140222

In the last 20 years, femoroacetabular impingement has been at the forefront of clinical practice as a cause of hip pain in young adults. As arthroscopic techniques for the hip continue to evolve, the possible presence of a new group of conditions creating mechanical conflict in and around the hip joint (ischiofemoral, subspine and iliopsoas impingement) has recently been elucidated whilst interest in already known ‘impingement’ syndromes (pelvic-trochanteric and pectineofoveal impingement) is now revived. This article attempts to increase awareness of these relatively uncommon clinical entities by describing their pathomorphology, contact mechanics, treatment and published results available to present. It is hoped that such knowledge will diversify therapeutic options for the clinician, thereby improving outcomes in a small but not negligible portion of patients with previously unexplained persistent symptoms. PMID:27011843

Anteriorhip pain can be difficult to diagnose due to the many pathologies and overlapping pain patterns that exist in the hip region. Clinical findings of pain at the anterior inferior iliac spine with passive hip flexion, proximal quadriceps pain and weakness, and painful impingement tests of the hip may be indicative of subspine hipimpingement. This report describes the diagnosis and treatment of anteriorhip pain, including subspine impingement and femoroacetabular impingement in an elite weightlifter. This case also describes how with the correct diagnosis and treatment, the athlete returned to play to her previous level of sport 11 months after a complex hip injury. PMID:27618239

Objective To outline the clinical presentation, physical examination findings, diagnostic criteria, and management options of femoroacetabular impingement (FAI). Sources of information PubMed was searched for relevant articles regarding the pathogenesis, diagnosis, treatment, and prognosis of FAI. Main message In recent years, FAI has been increasingly recognized as a potential precursor and an important contributor to hip pain in the adult population and idiopathic hip osteoarthritis later in life. Femoroacetabular impingement is a collection of bony morphologic abnormalities of the hip joint that result in abnormal contact during motion. Cam-type FAI relates to a non-spherical osseous prominence of the proximal femoral neck or head-neck junction. Pincer-type FAI relates to excessive acetabular coverage over the femoral head, which can occur owing to several morphologic variants. Patients with FAI present with chronic, deep, or aching anterior groin pain most commonly in the sitting position, or during or after activity. Patients might also experience occasional sharp pains during activity. A thorough history should be taken that includes incidence of trauma and exercise frequency. A physical examination should be performed that includes a full hip, low back, and abdominal examination to assess for alternate causes of anterior groin pain. Diagnosis of FAI should be confirmed with radiography. Femoroacetabular impingement can be managed conservatively with rest, modification of activities, medications, and physiotherapy, or it can be treated surgically. Conclusion Femoroacetabular impingement is an important cause of anterior groin pain. Early recognition and intervention by the primary care provider might be critical to alleviating morbidity and preventing FAI progression. PMID:26668284

Hip labral impingement can cause labral tears and secondary paralabral cyst formation. Femoroacetabular impingement is the main cause of labral impingement, but other conditions such as iliopsoas tendon impingement are described. There is no description of labral cyst resulting from psoas impingement treated arthroscopically in the literature. We present the case of a young sportsman with groin pain caused by psoas impingement with a labral tear and secondary paralabral cyst who was treated arthroscopically by cyst debridement, psoas tenotomy, and labral repair. PMID:22840990

Athletic pubalgia is a painful and complex syndrom encountered by athletes involved in pivoting and cutting sports such as hockey and soccer. To date, there is no real consensus on the criteria for a reliable diagnostic, the different investigations, and the appropriate therapy. Current literature underlines intrinsic and extrinsic factors contributing to athletic pubalgia. This review article reports upon two novelties related to the issue: the importance and efficience of prevention program and the association of femoro-acetabular impingement with the pubalgia. PMID:25141564

Anteriorhip pain is a common complaint with many possible causes. Apophyseal avulsion and slipped capital femoral epiphysis should not be overlooked in adolescents. Muscle and tendon strains are common in adults. Subsequent to accurate diagnosis, strains should improve with rest and directed conservative treatment. Osteoarthritis, which is diagnosed radiographically, generally occurs in middle-aged and older adults. Arthritis in younger adults should prompt consideration of an inflammatory cause. A possible femoral neck stress fracture should be evaluated urgently to prevent the potentially significant complications associated with displacement. Patients with osteitis pubis should be educated about the natural history of the condition and should undergo physical therapy to correct abnormal pelvic mechanics. "Sports hernias," nerve entrapments and labral pathologic conditions should be considered in athletic adults with characteristic presentations and chronic symptoms. Surgical intervention may allow resumption of pain-free athletic activity. PMID:10537384

Background. For a long time it has been accepted that the main problem in the anterior knee pain (AKP) patient is in the patella. Currently, literature supports the link between abnormal hip function and AKP. Objective. Our objective is to investigate if Cam femoroacetabular impingement (FAI) resolution is related to the outcome in pain and disability in patients with chronic AKP recalcitrant to conservative treatment associated with Cam FAI. Material and Methods. A retrospective study on 7 patients with chronic AKP associated with FAI type Cam was performed. Knee and hip pain were measured with the visual analogue scale (VAS), knee disability with the Kujala scale, and hip disability with the Nonarthritic Hip Score (NAHS). Results. The VAS knee pain score and VAS hip pain score had a significant improvement postoperatively. At final follow-up, there was significant improvement in all functional scores (Kujala score and NAHS). Conclusion. Our finding supports the link between Cam FAI and AKP in some young patients. Assessment of Cam FAI should be considered as a part of the physical examination of patients with AKP, mainly in cases with pain recalcitrant to conservative treatment. PMID:26451254

Background. For a long time it has been accepted that the main problem in the anterior knee pain (AKP) patient is in the patella. Currently, literature supports the link between abnormal hip function and AKP. Objective. Our objective is to investigate if Cam femoroacetabular impingement (FAI) resolution is related to the outcome in pain and disability in patients with chronic AKP recalcitrant to conservative treatment associated with Cam FAI. Material and Methods. A retrospective study on 7 patients with chronic AKP associated with FAI type Cam was performed. Knee and hip pain were measured with the visual analogue scale (VAS), knee disability with the Kujala scale, and hip disability with the Nonarthritic Hip Score (NAHS). Results. The VAS knee pain score and VAS hip pain score had a significant improvement postoperatively. At final follow-up, there was significant improvement in all functional scores (Kujala score and NAHS). Conclusion. Our finding supports the link between Cam FAI and AKP in some young patients. Assessment of Cam FAI should be considered as a part of the physical examination of patients with AKP, mainly in cases with pain recalcitrant to conservative treatment. PMID:26451254

The modified mid-anterior portal is a utilitarian hip arthroscopy working portal that permits dual-portal comprehensive surgery for femoroacetabular impingement and related chondrolabral procedures without the need for interportal exchange. Its distal location facilitates labral reparative and reconstructive procedures while minimizing iatrogenic acetabular chondral damage. The relatively lateral location permits instrument navigation not only along the anterosuperior acetabular rim and anterolateral proximal femur typically required for acetabuloplasty and femoroplasty but even to the posterior regions of the hip in cases of global pincer femoroacetabular impingement and posterior extensions of cam morphology and the anteromedial proximal femur while avoiding direct injury to the lateral femoral cutaneous nerve. PMID:25276606

We identified and compared the impingent-free range of motion (ROM) and subluxation potential for native hip, femoral head resurfacing (FHR), and total hip arthroplasty (THA). These constructs were also compared both with and without soft tissue to elucidate the role of the soft tissue. Five fresh-frozen bilateral hip specimens were mounted to a six-degree of freedom robotic manipulator. Under load-control parameters, in vivo mechanics were recreated to evaluate impingement free ROM, and the subluxation potential in two "at risk" positions for native hip, FHR, and THA. Impingement-free ROM of the skeletonized THA was greater than FHR for the anterior subluxation position. For skeletonized posterior subluxations, stability for THA and FHR constructs were similar, while a different pattern was observed for specimens with soft tissues intact. FHR constructs were more stable than THA constructs for both anterior and posterior subluxations. When the femoral neck is intact the joint has an earlier impingement profile placing the hip at risk for subluxation. However, FHR design was shown to be more stable than THA only when soft tissues were intact. PMID:23494830

Background: Cam femoroacetabular impingement is caused by a misshapen femoral head with a reduced head neck offset, commonly in the anterolateral quadrant. Friction in flexion, adduction and internal rotation causes limitation of the hip movements and pain progressively leading to labral and chondral damage and osteoarthritis. Surgical hip dislocation described by Ganz permits full exposure of the hip without damaging its blood supply. An osteochondroplasty removes the bump at the femoral head neck junction to recreate the offset for impingement free movement. Materials and Methods: Sixteen patients underwent surgery with surgical hip dislocation for the treatment of cam femoroacetabular impingement by open osteochondroplasty over last 6 years. Eight patients suffered from sequelae of avascular necrosis (AVN). Three had a painful dysplastic hip. Two had sequelae of Perthes disease. Three had combined cam and pincer impingement caused by retroversion of acetabulum. All patients were operated by the trochanteric flip osteotomy with attachments of gluteus medius and vastus lateralis, dissection was between the piriformis and gluteus minimus preserving the external rotators. Z-shaped capsular incision and dislocation of the hip was done in external rotation. Three cases also had subtrochanteric osteotomy. Two cases of AVN also had an intraarticular femoral head reshaping osteotomy. Results: Goals of treatment were achieved in all patients. No AVN was detected after a 6 month followup. There were no trochanteric nonunions. Hip range of motion improved in all and Harris hip score improved significantly in 15 of 16 cases. Mean alpha angle reduced from 86.13° (range 66°–108°) to 46.35° (range 39°–58°). Conclusion: Cam femoroacetabular Impingement causing pain and limitation of hip movements was treated by open osteochondroplasty after surgical hip dislocation. This reduced pain, improved hip motion and gave good to excellent results in the short term. PMID

We present a case of a patient with chronic anterior knee pain (AKP) recalcitrant to conservative treatment who returned to our office for severe hip pain secondary to Cam femoroacetabular impingement (Cam FAI) at 10 months after the onset of knee pain. This case highlights the fact that the main problem is not in the patella but in the hip in some patients with AKP. We hypothesize that there is an external femoral rotation in order to avoid the impingement and therefore the hip pain in patients with Cam FAI. This functional femoral rotation could provoke a patellofemoral imbalance that may be, in theory, responsible for patellofemoral pain in this particular patient. In our case, Cam FAI resolution was related to the resolution of AKP. PMID:27247817

An association between hip pain and quadratus femoris muscle abnormality on magnetic resonance imaging (MRI) with concurrent narrowing of the ischiofemoral space has been reported in the recent literature. This raises the possibility that the muscle damage observed is due to ischiofemoral impingement. This diagnosis has been noted in middle-aged females either with or without a history of trauma or surgery, is a rarely described feature. We report here on a 31-year-old woman who presented with non-traumatic hip pain and evidence of narrowing of the ischiofemoral space and edema in the quadratus femoris. Nonsurgical treatment was administered, which relieved her hip pain. The diagnosis of ischiofemoral impingement should be considered in female patients complaining of hip pain without any other evident cause. PMID:27047901

Dislocation of the hip joint in adults is usually caused by high-energy trauma such as road traffic accidents or falls from heights. Posterior dislocation is observed in most cases. However, atraumatic anterior dislocation of the hip joint is extremely rare. We present a case of atraumatic anterior dislocation of the hip joint that was induced by an activity of daily living. The possible causes of this dislocation were anterior capsule insufficiency due to developmental dysplasia of the hip, posterior pelvic tilt following thoracolumbar kyphosis due to vertebral fracture, and acetabular anterior coverage changes by postural factor. Acetabular anterior coverage changes in the sagittal plane were measured using a tomosynthesis imaging system. This system was useful for elucidation of the dislocation mechanism in the present case. PMID:26819791

In contemporary total hip arthroplasty, instability has been a complication in approximately 2% to 5% of primary surgeries and 5% to 10% of revisions. Due to the reduction in the incidence of wear-induced osteolysis that has been achieved over the last decade, instability now stands as the single most common reason for revision surgery. Moreover, even without frank dislocation, impingement and subluxation are implicated in a set of new concerns arising with advanced bearings, associated with the relatively unforgiving nature of many of those designs. Against that backdrop, the biomechanical factors responsible for impingement, subluxation, and dislocation remain under-investigated relative to their burden of morbidity. This manuscript outlines a 15-year program of laboratory and clinical research undertaken to improve the scientific basis for understanding total hipimpingement and dislocation. The broad theme has been to systematically evaluate the role of surgical factors, implant design factors, and patient factors in predisposing total hip constructs to impinge, sublux, and/or dislocate. Because this class of adverse biomechanical events had not lent itself well to study with existing approaches, it was necessary to develop (and validate) a series of new research methodologies, relying heavily on advanced finite element formulations. Specific areas of focus have included identifying the biomechanical challenges posed by dislocation-prone patient activities, quantifying design parameter effects and component surgical positioning effects for conventional metal-on-polyethylene implant constructs, and the impingement/dislocation behavior of non-conventional constructs, quantifying the stabilizing role of the hip capsule (and of surgical repairs of capsule defects), and systematically studying impingement and edge loading of hard-on-hard bearings, fracture of ceramic liners, confounding effects of patient obesity, and subluxation-mediated worsening of third body

The occurrence of total hipimpingement, whether or not accompanied by frank dislocation, holds substantial untoward clinical consequences, especially as less-forgiving advanced bearing implant designs come into ever more widespread use. Biomechanical aspects of impingement and dislocation have historically received relatively little scientific attention, although that situation is now rapidly changing. The present article reviews contemporary laboratory and clinical research on the impingement/dislocation phenomena, focusing particularly on how implant design variables, surgical implantation factors and patient activity each act individually and in concert to pose impingement and dislocation challenges. In recent years, several powerful new research methodologies have emerged that have greatly expanded the scope for clinical translation of systematic laboratory study. Transferring the findings from such research into yet better implant designs, and even better surgical procedures, offers encouragement that the clinical impact of this troublesome complication can be further reduced. PMID:19956356

Anteriorhip or groin pain is a common complaint for which people are referred for physical therapy. We have observed that people with anteriorhip pain often walk in greater hip extension than people without anteriorhip pain, and that the pain is reduced when they walk in less hip extension. Therefore, we investigated anteriorhip joint forces which may contribute to anteriorhip pain and examined the effect of end range hip extension on the anteriorhip joint force during gait. To do this, we used a 6 degree of freedom, 3-dimensional musculoskeletal model to estimate hip joint forces during gait. Within subjects, the maximum anteriorhip joint force for gait trials with the most hip extension was compared to the anteriorhip joint force for gait trials with the least hip extension. The musculoskeletal model indicated that increasing the maximum end range hip extension when walking results in an increase in the anteriorhip joint force when compared to walking in less hip extension. Walking in greater hip extension may result in an increase in the anteriorhip joint force, and thereby contribute to anteriorhip pain. The findings of this study provide some evidence supporting the use of gait modification to reduce anteriorhip force when treating people with anteriorhip pain. PMID:20934338

The mini-incision anterior approach in total hip replacement is not new, but uses a shorter incision than the traditional Hueter approach, typically only 6-8 cm in length. Despite its size, the single anterior incision allows good exposure. It is very atraumatic, preserves muscles and tendons, and allows the patient early mobilisation and fast postoperative recovery. Although, a special table (e.g., a Judet table) and specific tools (e.g., a curved reamer) are needed to perform hip replacement via the mini-anterior approach, any kind of hip prosthesis (cemented or uncemented) can be implanted. As there is a significant learning curve in mastering the mini-incision anterior approach, surgeons are advised to start with a longer incision and then to decrease its length with increasing experience. PMID:17657491

Abnormal or excessive force on the anteriorhip joint may cause anteriorhip pain, subtle hip instability and a tear of the acetabular labrum. We propose that both the pattern of muscle force and hip joint position can affect the magnitude of anterior joint force and thus possibly lead to excessive force and injury. The purpose of this study was to determine the effect of hip joint position and of weakness of the gluteal and iliopsoas muscles on anteriorhip joint force. We used a musculoskeletal model to estimate hip joint forces during simulated prone hip extension and supine hip flexion under 4 different muscle force conditions and across a range of hip extension and flexion positions. Weakness of specified muscles was simulated by decreasing the modeled maximum force value for the gluteal muscles during hip extension and the iliopsoas muscle during hip flexion. We found that decreased force contribution from the gluteal muscles during hip extension and the iliopsoas muscle during hip flexion resulted in an increase in the anteriorhip joint force. The anteriorhip joint force was greater when the hip was in extension than when the hip was in flexion. Further studies are warranted to determine if increased utilization of the gluteal muscles during hip extension and of the iliopsoas muscle during hip flexion, and avoidance of hip extension beyond neutral would be beneficial for people with anteriorhip pain, subtle hip instability, or an anterior acetabular labral tear. PMID:17707385

Objectives: The pathophysiology of femoroacetabular impingement (FAI) remains to be better understood. Only a fraction of all individuals with bony FAI morphology will ever develop hip symptoms or osteoarthritis. The purpose of the current study was to determine (1) rates of initial and subsequent symptom development in the contralateral hip of patients with symptomatic ipsilateral FAI and (2) to identify predictors of symptomatic contralateral FAI. Methods: The study cohort included 179 consecutive patients presenting for surgical treatment of FAI. Patients were excluded if they had previously underwent contralateral surgery. At baseline and postoperative follow-up time points, patients recorded standardized outcome questionnaires, including the presence of symptoms in the contralateral hip. Significant symptoms were defined as the presence of at least mild pain, while none or slight pain was not included. All patients underwent AP pelvis and bilateral 45 degree Dunn lateral radiographs at baseline. Patients developing symptoms in the contralateral hip were subclassified as having symptoms at presentation (initial symptoms) or developing symptoms during the follow-up period (symptom development). Patients were followed over a minimum of one year time period postoperatively. Multivariate logistic regression was performed to identify independent predictors of symptoms development. Results: The study cohort had a mean age of 30.2 years and included 60.3% females. FAI was classified as isolated cam in 63.1% (n=113), isolated pincer 1.1% (n=2), and combined type in 35.8% (n=64). Forty-two (23.5%) of patients had initial symptoms in the contralateral hip. Twenty-two additional hips developed symptoms during the follow-up period (16.1% of initially asymptomatic hips). For multivariate logistic regression of any symptoms development (initial or subsequent), competitive athletes (p=0.041) and contralateral HNO ratio on AP pelvis (p=0.009). However, the overall model poorly

The extra-articular impingement of the greater trochanter against the ileum is an underrated cause of early dislocation in total hip arthroplasty. In this preliminary study, the authors assess the effectiveness of an anterior longitudinal osteotomy of the greater trochanter for preventing dislocation. A total of 115 patients underwent a total hip arthroplasty through a posterolateral approach. All patients underwent clinical and radiological follow-up at 1, 3, and 6 months. No dislocation was reported. All patients demonstrated fast recovery of range of motion and walking. No trochanter fractures were observed. The osteotomy of the greater trochanter is an effective surgical technique that decreases anteriorimpingement and consequently lowers the dislocation rate in primary total hip arthroplasty. [Orthopedics. 2015; 38(8):490-493.]. PMID:26313167

The anterior approach for total hip replacements has recently gained popularity. Some authors report faster recoveries and decreased dislocation rated with no increased risk of complications. However others claim no difference in outcomes when compared to other approaches yet an increase in complication rates. This paper provides a brief history of the approach, discusses various indications and contraindications, preoperative considerations, surgical techniques, and postoperative protocols. PMID:26977549

There is growing subgroup of patients with poor outcomes after hip arthroscopy for intra-articular pathology suggesting unrecognized cause(s) of impingement may exist. Extra-articular hipimpingement (EHI) is an emerging group of conditions that have been associated with intra-articular causes of impingement and may be an unrecognized source of pain. EHI is caused by abnormal contact between the extra-articular regions of the proximal femur and pelvis. This review discusses the most common forms for EHI including: central iliopsoas impingement, subspine impingement, ischiofemoral impingement, and greater trochanteric-pelvic impingement. The clinical presentation of each pathology will be discussed since EHI conditions share similar clinical features as the intra-articular pathology but also contain some unique characteristics. PMID:27069266

The current literature on femoroacetabular impingement (FAI) is focused on acetabular orientation and femoral head asphericity, with little emphasis on the effect of version of the femoral neck. A biomechanical model was developed to determine the causative effect, if any, of femoral retroversion on hip contact stress and, if present, delineate the type of FAI with femoral neck retroversion. Five pairs of cadaveric hips (n = 10) were tested by loading the hip in 90° of flexion and measured the peak joint pressure and the location of the peak joint pressure. The experiment was repeated after performing a subtrochanteric osteotomy and retroverting the proximal femur by 10°. Ten hips were successfully tested, with one hip excluded due to an outlier value for peak joint pressure. Retroversion of the proximal femur significantly increased the magnitude of mean peak joint pressure. With retroversion, the location of the peak joint pressure was shifted posteroinferiorly in all cases. In conclusion, femoral neck retroversion increases peak joint pressure in the flexed position and may act as a cause of femoroacetabular impingement. The location of peak joint pressure suggests a pincer-type impingement with retroversion. The version of femoral neck should be assessed as a possible causative factor in patients with FAI, especially those with pincer-type impingement. PMID:27011851

Femoroacetabular impingement is a relatively recently described condition in which an abnormally shaped proximal part of the femur or acetabular overcoverage causes interference between the femoral head-neck junction and the acetabular rim. These disorders are now recognized as common causes of prearthritic hip pain and secondary osteoarthritis. Two mechanisms have been described. Cam-type impingement is caused by insufficient concavity of the femoral head-neck junction. Pincer-type impingement is caused by overcoverage of the femoral head by the acetabulum. Abnormal femoroacetabular abutment predisposes affected patients to labral tears, articular cartilage damage, and premature osteoarthritis. Early diagnosis of hip disease and referral for specialized care may optimize clinical outcomes and alter the natural history of these disorders. This review aims to describe this syndrome and to review the contemporary concepts of the etiology and surgical treatment of the disorder. PMID:22164944

This report describes the arthroscopic management of a case of incarcerating pincer-type femoroacetabular impingement. The hip joint had a marked restriction of range of motion and secondary pain as a result of osteophytes wrapping around the femoral head down the femoral neck. The patient was treated with staged bilateral hip arthroscopy. The procedures were initially performed through the peripheral compartment to remove the incarcerating acetabular rim, followed by arthroscopy of the central compartment with acetabuloplasty and femoral head osteochondroplasty. The patient's treatment has led to an excellent clinical and radiographic result at 24 months' follow-up despite an unrelated pelvic fracture sustained in the postoperative period. This technique emphasizes the capabilities of hip arthroscopy in advanced cases of femoroacetabular impingement as an alternative to arthroplasty for patients with healthy articular cartilage. PMID:24749038

Anterior traumatic dislocations of the hip are much less common than posterior dislocations. To date, 14 cases of open anterior dislocation of the hip associated with such injuries, acetabular and femoral head fractures and femoral vascular and nerve damage have been reported. We present a case of a 23-year-old male who sustained open anterior dislocation of the hip with ipsilateral fracture of the greater trochanter after an accident on the public highway. Additional lesions included an iliac wing fracture and a perineal wound. We report this case because of the rarity and seriousness of this injury due to its progressive complications and difficulties related to its management, which are typical to a developing country like ours. PMID:27247749

Hip osteoarthritis (OA) leads to significant functional limitations and economic burden. If modifiable risk factors for hip OA are identified, it may be possible to implement preventative measures. Bony abnormalities associated with acetabular dysplasia (AD) and femoroacetabular impingement (FAI) have been recently implicated as risk factors for hip osteoarthritis (OA). The purpose of this focused review is to summarize the available evidence describing the relationship between bony abnormalities and hip OA. A librarian-assisted database search using PubMed, Embase and Central was performed. Relevant articles were identified and assessed for inclusion criteria. The authors reviewed cohort and case control studies that reported on the association between abnormal hip morphology and hip OA. The available literature suggests that an association exists between bony abnormalities found in AD and FAI and hip OA and preliminary evidence suggests that AD is a risk factor for OA, however these conclusions are based on limited evidence. Prospective, longitudinal studies are needed to confirm the causal relationship between abnormal hip morphology and the future development of hip OA. PMID:22108232

Background Impingement events, in addition to their role immediately proximate to frank dislocation, hold the potential to damage new-generation hard-on-hard bearings as a result of the relatively unforgiving nature of the materials and designs. Because of the higher stiffness and tighter design tolerances of metal-on-metal and ceramic implants, surgical positioning plausibly has become even more important. Questions/purposes We asked (1) whether, and under what cup orientation conditions, hard-on-hard impingements might challenge implant material failure strength; and (2) whether particle generation propensity at impingement and egress sites would show similar dependence on cup orientation. Methods Realistic computational simulations were enabled by multistage finite element analyses, addressing both global construct motion and loading, and focal stress concentrations at neck impingement and rim egress sites. The global model, validated by a cadaveric simulation in a servohydraulic hip simulator, included both hardware components and advanced anisotropic capsule characterization. Parametric computational runs explored the effect of cup orientation for both ceramic-on-ceramic and metal-on-metal bearing couples for two distinct motion sequences associated with dislocation. Results Stress concentrations from impingement increased nearly linearly with increased cup tilt and with cup anteversion. In some situations, peak values of stress approached or exceeded 1 GPa, levels challenging the yield strength of cobalt-chromium implants, and potentially the fracture strength of ceramics. The tendency for impingement events to generate debris, indexed in terms of a new scraping severity metric, showed orientation dependences similar to that for bulk material failure. Conclusions Damage propensity arising from impingement events in hard total hip bearings is highly orientation-dependent. PMID:20953853

Presents a literature review of the impact of impingement in fishery resources at different power plants in the United States, covering publications of 1976-77. Consideration is given to engineering studies and biological effects for reducing impingement. A list of 96 references is also presented. (HM)

The purpose of this review is to examine the validity of positive claims regarding the direct anterior approach (DAA) with a fracture table for total hip arthroplasty. Recent literature regarding the DAA was searched and specific claims investigated including improved early outcomes, speed of recovery, component placement, dislocation rates, and complication rates. Recent literature is positive regarding the effects of total hip arthroplasty with the anterior approach. While the data is not definitive at present, patients receiving the anterior approach for total hip arthroplasty tend to recover more quickly and have improved early outcomes. Component placement with the anterior approach is more often in the “safe zone” than with other approaches. Dislocation rates tend to be less than 1% with the anterior approach. Complication rates vary widely in the published literature. A possible explanation is that the variance is due to surgeon and institutional experience with the anterior approach procedure. Concerns remain regarding the “learning curve” for both surgeons and institutions. In conclusion, it is not a matter of should this approach be used, but how should it be implemented. PMID:23362470

Direct anterior total hip arthroplasty has become increasingly more popular among arthroplasty surgeons, in large part due to the use of an intramuscular interval and desire to reduce soft tissue damage. Several studies have now been published comparing the anterior intramuscular to other commonly used approaches, and many studies have published complication rates on large series of patients. Review of comparative studies indicates direct anteriorhips tend towards shorter hospital stays and high rates of patients discharged to home. Although some studies show evidence of early benefit in functional outcomes, there is no strong evidence that the anterior approach provides any long term functional improvements compared to other approaches. Additionally, evidence to support reduced damage to soft tissue may not translate to certain clinical significance. Rates of intra-operative femur fracture, operative time and blood loss rates are notably higher for those developing familiarity with this approach. However, when surgeons have performed a modest number of procedures, the complication rates tend to markedly decrease in most studies to levels comparable to other approaches. Accuracy of component positioning also favors the anterior approach in some studies. This review summarizes the available literature comparing the direct anterior to other approaches for total hip arthroplasty and provides a comprehensive summary of common complications. PMID:26925380

Fat is not just used by the body as bulk tissue. In addition to its role in storing energy and regulating hormone action, fat is used in some parts of the body for its mechanical properties. The anatomy of anterior knee fat is more complex than it appears at first sight and is capable of withstanding considerable compressive and shear stress. Specific lesions occur when such mechanical stress exceeds the physiological limits and are yet little known. Superficial fat can be the site of either acute injury by closed degloving called the Morel-Lavallée lesion or chronic injury, when subject to repeat excessive shear forces, due to more complex and less well-defined disruptions that result in pseudo-bursitis. There are three main anterior, intracapsular and extrasynovial fat pads in the knee joint, which are the infrapatellar fat pad (IFP) or Hoffa's fat pad, the quadriceps fat pad and the prefemoral fat pad. The IFP plays an important role as a mechanical shock absorber and guides the patella tendon and even the patella itself during flexion-extension movements. In response to repeated excessive stress, an inflammatory reaction and swelling of the IFP is first observed, followed by a fibrotic reaction with metaplastic transformation into fibrous, cartilaginous or bone tissue. More rarely, the two other deep fat pads (quadriceps and prefemoral) can, if subject to repeated stress, undergo similar restructuring inflammatory reactions with metaplasia resulting in tissue hardening, anterior pain and partial loss of function. PMID:27118690

A test facility was built to measure the impingement convective heat transfer coefficient for a high impact polystyrene (HIPS) liner sheet which was heated by an array of air slot nozzles. A HIPS liner sheet having a thickness of 6 mm is a typical material used for inside shells of refrigerators. The nozzle geometry was optimally designed. The pressure drops through the nozzles, the velocities at the exits of nozzles, temperatures on the sheet surface and in the sheet center were measured. The impingement heat transfer coefficient on the sheet was determined using the measured sheet temperature history in conjunction with an inverse analysis which was based on a one-dimensional transient heat conduction model. The effect of air flow rate ranging from 8 to 32 m/s on the heat transfer coefficient is discussed.

We evaluated 70 patients (71 hips) who underwent complex total hip arthroplasty (THA) through the combined anterior and posterior approach. Sixty-five patients (32 dislocated hips and 34 ankylosed hips) were followed-up at a minimum of 3 years (median, 6 years; range, 3-10 years). Seven patients (10.6%), who had transient paresthesia on the anterior thigh, recovered within 3 months. All patients had a good clinical outcome in terms of range of motion, pain and recovery of walking. At the latest follow-up, all prostheses had bone-ingrown stability without any detectable wear or osteolysis. The combined approach allows an excellent exposure of the acetabulum for accurate cup alignment, leg lengthening and mobilization of joint in complex THA without trochanteric osteotomy, excessive abductor release and femoral shortening osteotomy. PMID:25682205

In order to assess outcome and possible predictors of early good results, a prospective study on 22 patients who were treated with save surgical hip dislocation for symptomatic isolated cam-type femoroacetabular impingement (FAI) was performed. After a follow-up of 6 and 12 months, standard clinical and radiographic parameters were recorded. A statistically significant improvement of the clinical status according to the Harris hip score could be assessed at six months (p-value = 0.003) and 12 months (p-value = 0.001) post-surgery. By comparing standard clinical and radiographic preoperative parameters with various follow-up outcomes, we revealed no specific parameter with predictive value. These findings are important for centers that have just started to use this surgical technique and are still identifying their learning curve. PMID:21719395

In order to assess outcome and possible predictors of early good results, a prospective study on 22 patients who were treated with save surgical hip dislocation for symptomatic isolated cam-type femoroacetabular impingement (FAI) was performed. After a follow-up of 6 and 12 months, standard clinical and radiographic parameters were recorded. A statistically significant improvement of the clinical status according to the Harris hip score could be assessed at six months (p-value = 0.003) and 12 months (p-value = 0.001) post-surgery. By comparing standard clinical and radiographic preoperative parameters with various follow-up outcomes, we revealed no specific parameter with predictive value. These findings are important for centers that have just started to use this surgical technique and are still identifying their learning curve. PMID:21719395

The normal value of alpha angle is controversial. The aim of this study was to compare the alpha angle in asymptomatic volunteers versus patients who had undergone surgery for symptomatic cam-type femoroacetabular impingement (FAI) and determine a diagnostic cut-off value for symptomatic cam impingement. This is a diagnostic test study. Cases were defined as those patients who had undergone surgery for symptomatic cam or mixed type FAI. Controls were defined as asymptomatic volunteers, with no history of hip pain who had undergone a computed tomography (CT) scan of the abdomen and pelvis for a non-joint or bone-related reason. In both groups, the alpha angle was measured in an oblique axial CT reconstruction of the femoral neck. A logistic regression model was first estimated and a receiver operating characteristics (ROC) curve was then calculated. The diagnostic cut-off value selected was the one that maximizes sensitivity and specificity. Data were analysed from 38 consecutive cases of cam or mixed FAI and 101 controls. The average alpha angle was 67°(±12°) among cases and 48°°(±5°) among controls. An odds ratio of 1.28 [1.18-1.39] was obtained. A ROC curve of 0.96 [0.93-0.99] was calculated, and using an alpha angle of 57° as the diagnostic cut-off value, provided a sensitivity of 92% and a specificity of 95%. If a patient complains of hip pain and an alpha angle of 57° is found in CT, strongly suggest that cam impingement is causing the pain. PMID:27583162

The normal value of alpha angle is controversial. The aim of this study was to compare the alpha angle in asymptomatic volunteers versus patients who had undergone surgery for symptomatic cam-type femoroacetabular impingement (FAI) and determine a diagnostic cut-off value for symptomatic cam impingement. This is a diagnostic test study. Cases were defined as those patients who had undergone surgery for symptomatic cam or mixed type FAI. Controls were defined as asymptomatic volunteers, with no history of hip pain who had undergone a computed tomography (CT) scan of the abdomen and pelvis for a non-joint or bone-related reason. In both groups, the alpha angle was measured in an oblique axial CT reconstruction of the femoral neck. A logistic regression model was first estimated and a receiver operating characteristics (ROC) curve was then calculated. The diagnostic cut-off value selected was the one that maximizes sensitivity and specificity. Data were analysed from 38 consecutive cases of cam or mixed FAI and 101 controls. The average alpha angle was 67°(±12°) among cases and 48°°(±5°) among controls. An odds ratio of 1.28 [1.18–1.39] was obtained. A ROC curve of 0.96 [0.93–0.99] was calculated, and using an alpha angle of 57° as the diagnostic cut-off value, provided a sensitivity of 92% and a specificity of 95%. If a patient complains of hip pain and an alpha angle of 57° is found in CT, strongly suggest that cam impingement is causing the pain. PMID:27583162

Objectives: Cam-type femoroacetabular impingement (FAI) causes a shearing and delamination injury to the acetabular articular cartilage due to a mismatch between the size of the femoral head and the acetabulum. This mechanism is thought to lead to early osteoarthritis in this population. Cam decompression has been advocated to eliminate impingement, with the ultimate goal of halting the progression of articular cartilage delamination. Although outcomes following this procedure in the young adult population have been favorable at short and medium term follow up, it is not known whether the articular cartilage itself is protected from further injury by changing the biomechanics of the joint with decompression of the cam morphology. The purpose of this study is to compare the pre- and post-operative integrity of the acetabular articular cartilage using T2 mapping to determine if hip arthroscopy is protective of the articular cartilage at short- to medium term follow up. Methods: Males between 18 and 35 years of age who had pre-operative T2 mapping MRIs, underwent hip arthroscopy for cam or mixed-type FAI with an alpha angle greater than 50°, and had at least 2 year follow-up were identified. Post-operative MRIs were performed and T2 relaxation times in the transition zone and weight bearing articular cartilage in the anterosuperior acetabulum at deep and superficial chondral layers were recorded at nine points on three sagittal sequences on pre and post-operative MRIs. A paired t-test was used to compare T2 relaxation values between pre-operative and post-operative scans. Results: Eleven hips were evaluated. Mean age was 26.3 years (range 21 - 35). Mean follow up time to post-operative T2 mapping MRI was 2.6 years (range 2.4 - 2.7). The change in T2 relaxation time was not significantly different between pre- and post-operative MRI scans for any of the nine regions in the deep zone of the acetabular cartilage (p=0.065 - 0.969) or the superficial zone of the

Objectives: Previous studies have shown that professional hockey players return to sport at a high rate following hip arthroscopy. The average length of a National Hockey League (NHL) career has been reported to be 5.5 years, and it is unknown how long players continue to play after hip arthroscopy. The purpose of this study was 1) to determine predictors of length of career in players following hip arthroscopy for treatment of symptomatic femoroacetabular impingement (FAI), and 2) investigate the rate of those who continue to play professional hockey a minimum of 5 years after hip arthroscopy. Methods: Seventy professional hockey players underwent hip arthroscopy for FAI between 2005 and 2010 by a single surgeon. Data was retrieved from NHL.com regarding the duration of each player’s professional career. In addition, position played, draft position, age at time of surgery, and surgical details were also used in data analysis. Results: Our cohort included thirteen players that were centers, 15 defensemen, 20 goalies, and 22 wings. The average overall draft number was 57 (range 1 to 228), and average age at surgery was 27 years (range 17 to 38). Forty of the 70 athletes (57%) continued to play professionally a minimum of 5 years after hip arthroscopy. As of the most recent 2015 season, the average NHL length of career was 13 years (range 8 to 23 years), with an average of 6.9 years played following hip arthroscopy. Therre was no different in length of career and years played when goalies were compared to other players(p=0.760). Length of career and years played after arthroscopy correlated with age at surgery (r=0.799 and r=-0.408). Players who played 5 or more years after arthroscopy were significantly younger than those who did not (25 vs. 30 years, p=0.001). Sixty-five players (93%) had labral repair and 5 (7%) had labral reconstruction. There were no differences in length of career or years played after arthroscopy based on type of labral treatment (p=0

This work presents a finite element analysis of Anterior Cruciate Ligament (ACL) impingement against the intercondylar notch during tibial external rotation and abduction, as a mechanism of noncontact ACL injuries. Experimentally, ACL impingement was measured in a cadaveric knee in terms of impingement contact pressure and six degrees-of-freedom tibiofemoral kinematics. Three-dimensional geometries of the ACL, femur and tibia were incorporated into the finite element model of the individual knee specimen. A fiber-reinforced model was adopted, which accounts for the anisotropy, large deformation, nonlinearity and incompressibility of the ACL. With boundary conditions specified based on the experimental tibiofemoral kinematics, the finite element analysis showed that impingement between the ligament and the lateral wall of intercondylar notch could occur when the knee 45° was externally rotated at 29.1° and abducted at 10.0°. Strong contact pressure and tensile stress occurred at the impinging and nonimpinging sides of the ligament, respectively. The impingement force and contact area estimated from the model matched their counterparts from the corresponding cadaver experiment. The modeling and experimental approach provides a useful tool to characterize potential ACL impingement on a knee-specific basis, which may help elucidate the ACL injury mechanism and develop more effective treatments. PMID:20413123

Ankle impingement is a syndrome that encompasses a wide range of anterior and posterior joint pathology involving both osseous and soft tissue abnormalities. In this review, the etiology, pathoanatomy, diagnostic workup, and treatment options for both anterior and posterior ankle impingement syndromes are discussed. PMID:27608626

Femoro-acetabular impingement has been proposed as a causative factor of primary hip osteoarthritis. However, primary osteoarthritis of the hip is infrequent in Japan and other Asian countries, even though the hips of Asians frequently sustain impingement, since the Asian lifestyle commonly requires a larger range of hip motion than the Western lifestyle. Therefore, using open-configuration MRI, we investigated whether impingement actually occurs during some traditional Japanese hip positions. The hips of 5 healthy Japanese females were examined in 5 sitting postures: 1) sitting straight; 2) bowing while sitting straight; 3) sitting cross-legged; 4) W-sitting; and 5) squatting. The impingement point was detected by multiple plane reconstructed (MPR) views along with the acetabular rim depicted circumferentially. Impingement was considered to have occurred when, on MRI, the anterior femoral head-neck junction approached the acetabular rim and the femoral head was seen to float from the bottom of the acetabulum with the acetabular rim acting as a fulcrum. Impingement was observed in all volunteers in the W-sitting position, and in 2 of 5 volunteers during squatting. These findings show that impingement occurs frequently during daily Japanese activities. Thus, depending on race, femoro-acetabular impingement might not always cause primary osteoarthritis of the hip. (c) 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:1582-1588, 2007. PMID:17600811

Gait analysis is an objective tool that has been used to assess and monitor treatment for many musculoskeletal conditions. Recently, it has been used to assess the impact of femoro-acetabular impingement (FAI) on the hip and lower limb movements. There have been a fairly limited number of studies published so far reporting unexpected and inconsistent results, which calls for more research to be conducted in this arena. In the light of the limited data available, it has been challenging to reconcile the contradictions in some of these results, and therefore no coherent conclusions could be drawn. In this short article, we attempt to explain some of the abnormal kinematic and kinetic patterns associated with FAI by highlighting similarities between the gait seen in early osteoarthritis (OA) and that of FAI. We also propose an approach for future research in this field and emphasise the importance of quantifying early OA in FAI based on magnetic resonance imaging (MRI) scans and the amount of chondral damage seen during open or arthroscopic surgery. PMID:24687267

Introduction: Mucoid degeneration of cruciate ligament is well known entity, but symptomatic lesions are rare. It is even rarer to find a symptomatic posterior cruciate ligament mucoid degeneration than anterior cruciate ligament. Case Report: A 65-years-old female presented to our hospital complaining of pain in right knee joint on terminal extension since 6 months. On clinical examination, there was a flexion deformity of 5 degree and a further flexion of 150 degree with mild pain exacerbated by extension. MRI of the right knee joint showed a diffusely thickened posterior cruciate ligament (PCL) with increased intra ligamentous signal intensity on T2-weighted images. The arthroscopic findings of grossly thickened PCL with a yellowish hue are characteristic and the PCL was filled with a yellowish substance. We excised the yellowish substance from the PCL as precisely as possible not to damage the remaining PCL fiber (Limited Debulking). We did notchplasty of lateral wall and roof to accommodate the Anterior Cruciate Ligament and avoid impingement. Conclusion: Posterior cruciate ligament may enlarge significantly and may push the Anterior Cruciate Ligament in the notch and may lead to the anterior cruciate ligament (ACL) impingement symptoms. Partial Debulking of Posterior Cruciate Ligament and notchplasty is effective treatment with immediate postoperative pain relief and good functional results. PMID:27299097

Femoroacetabular impingement (FAI) is a common cause of hip pain, and when indicated, can be successfully managed through open surgery or hip arthroscopy. The goal of this review is to describe the different approaches to the surgical treatment of FAI. We present the indications, surgical technique, rehabilitation, and complications associated with (1) open hip dislocation, (2) reverse periacetabular osteotomy, (3) the direct anterior “mini-open” approach, and (4) arthroscopic surgery for FAI. PMID:26697431

Objective The purpose of this case report is to describe the diagnostic value of ultrasonography (US) in a patient with injury to the lateral ligaments of the ankle with concomitant ankle joint osteoarthritis and anteriorimpingement. Clinical Features A 28-year-old male had a history of an inversion injury of the left ankle. Diagnostic US of the left ankle using an 8- to 15-MHz linear array transducer demonstrated a full thickness tear of the anterior talofibular ligament, partial thickness tearing of the calcaneofibular ligament, and laxity of the ankle with varus stress testing. In addition, US was able to demonstrate degeneration of the ankle and talonavicular joints and anteriorimpingement with dorsiflexion. Osteoarthritic changes were confirmed with radiography. Other US findings included remote deltoid ligamentous complex injury, multiple sites of tenosynovitis, and a large ankle joint effusion with synovial hypertrophy and synovitis. Intervention and Outcome Using US, an accurate diagnosis was established with respect to the pathology and functional impairments of the patient’s ankle. Conclusion This case report exemplifies the value and utility of US in diagnosing derangement in ligamentous, tendinous, articular, and osseous injuries of the ankle. PMID:26793038

The surgical treatment of femoroacetabular impingement (FAI) often involves femoral osteochondroplasty. One risk of this procedure is fracture of the femoral neck. We developed a finite element (FE) model to investigate the relationship between depth of resection and femoral neck stress. CT data were used to obtain the geometry of a typical cam-type hip, and a 3D FE model was constructed to predict stress in the head-neck after resection surgery. The model accounted for the forces acting on the head and abductor muscular forces. Bone resection was performed virtually to incremental resection depths. The stresses were calculated for five resection depths and for five different activities (i) standing on one leg (static case); (ii) two-to-one-to-two leg standing; (iii) normal walking; (iv) walking down stairs; and (v) a knee bend. In general, both the average Von Mises stresses and the area of bone that yielded significantly increased at a resection depth of ≥10 mm. The knee bend and walking down stairs demonstrated the highest stresses. The FE model predicts that fracture is likely to occur in the resection area first following removal of a third (10 mm) or more of the diameter of the femoral neck. We suggest that when surgeons perform osteochondroplasty for hipimpingement, the depth of resection should be limited to 10 mm. PMID:22707347

Introduction: The anterior dislocation of the hip represents only a small percentage of all hip dislocations: 85% are posterior. Most commonly associated with this dislocation is a fracture of the femoral head and, in rare cases, a femoral neck fracture. We have found in literature no report of an anterior dislocation of the hip associated with femoral neck fracture, pelvic retention of the head and ureteral fistula. We report such a case of a 68 year old male. Case Report: A 68 year old male was presented to our attention, following a severe injury of the hip when falling from a high bridge, with severe pain in the hip and a clinical aspect of femoral neck fracture. The X-ray confirmed the femoral neck fracture but following an anterior dislocation with the head retained into the pelvis. The patient also had hematuria. An Austin Moore prosthesis was implanted for the femoral neck fracture and the head was extracted by the urologist by a new abdominal incision. Urological evaluation revealed a fistula of the ureter, treated by an internal drainage for three months. One month later the Moore prosthesis was extracted and the patient had a Girldestone hip for 5 months. Revision with a Muller cemented prosthesis had a normal evolution. Conclusion: The anterior fracture dislocation of the hip with pelvic retention of the femoral head and ureteral fistula is a rare condition resulting from high energy trauma. A multidisciplinary team is necessary to diagnose and treat fracture and soft tissue lesions. Early diagnosis and treatment is necessary to avoid septic complications. PMID:27298980

... FAI. Because athletically active people may work the hip joint more vigorously, they may begin to experience pain ... the impingement can prevent future damage to the hip joint. However, not all of the damage can be ...

Background The cam deformity causes the anterosuperior femoral head to obstruct with the acetabulum, resulting in femoroacetabular impingement (FAI) and elevated risks of early osteoarthritis. Several finite element models have simulated adverse loading conditions due to cam FAI, to better understand the relationship between mechanical stresses and cartilage degeneration. Our purpose was to conduct a systematic review and examine the previous finite element models and simulations that examined hip joint stresses due to cam FAI. Methods The systematic review was conducted to identify those finite element studies of cam-type FAI. The review conformed to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and studies that reported hip joint contact pressures or stresses were included in the quantitative synthesis. Results Nine articles studied FAI morphologies using finite element methods and were included in the qualitative synthesis. Four articles specifically examined contact pressures and stresses due to cam FAI and were included in the quantitative synthesis. The studies demonstrated that cam FAI resulted in substantially elevated contact pressures (median = 10.4 MPa, range = 8.5–12.2 MPa) and von Mises stresses (median 15.5 MPa, range = 15.0–16.0 MPa) at the acetabular cartilage; and elevated maximum-shear stress on the bone (median = 15.2 MPa, range = 14.3–16.0 MPa), in comparison with control hips, during large amplitudes of hip motions. Many studies implemented or adapted idealized, ball-and-cup, parametric models to predict stresses, along with homogeneous bone material properties and in vivo instrumented prostheses loading data. Conclusion The formulation of a robust subject-specific FE model, to delineate the pathomechanisms of FAI, remains an ongoing challenge. The available literature provides clear insight into the estimated stresses due to the cam deformity and provides an assessment of its risks leading to early

Objectives: The objective of the current study was to evaluate patient reported outcomes and return to sport in a cohort of distinctly recreational and amateur level athletes following hip arthroscopy for femoroacetabular impingement (FAI). Methods: Following IRB approval, clinical data was retrospectively retrieved for 66 consecutive FAI patients (26 men, 40 women) who had undergone hip arthroscopy and identified themselves as recreational or amateur athletes on intake forms. Two-year patient-reported outcomes (PRO) included a sport-specific questionnaire, modified Harris Hip Score (mHHS), and Hip Outcome Scores with Activities of Daily Living (HOS-ADL) and Sports-Specific (HOS-SS) subscales were analyzed. Results: The mean age and BMI of all subjects was 26.8 ± 7.6 years and 23.9 ± 3.2 kg/m2, respectively. Athletes had withdrawn from sport for an average of 9.5 ± 6.7 months prior to surgery and on average required 9.7 ± 5.1 months to return to sport. After two years, all mean PRO scores had improved significantly (Figure 1), and 57 patients (92%) had returned to play and continued participation. Patients who had withdrawn from sport for greater than 8 months before surgery returned to sport significantly more slowly than those who had withdrawn for less than 8 months (p=0.01). Greater withdrawal from sport prior to surgery also correlated with lower postoperative improvements in HOS-ADL and HOS-SS scores. Bivariate analysis revealed that increasing body-mass index (BMI) was associated with lower improvements in PROs. Conclusion: Recreational athletes, following hip arthroscopy for FAI, return to play at a high rate. Increasing BMI and preoperative withdrawal from sport both significantly prolong return to play and diminish two-year PROs. Most return-to-play studies following hip arthroscopy for FAI have focused on professional athletes, with limited generalizability to the average sports medicine surgeon practice. This is the first study of its kind to focus

The direct anterior approach to the hip has been suggested to have several advantages compared to previously popular approaches through its use of an intra-muscular and intra-nervous interval between the tensor fasciae latae and sartorius muscles. Recent increased interest in tissue-sparing and minimally-invasive arthroplasty has given rise to a sharp increase in the utilization of direct anterior total hip arthroplasty. A number of variations of the procedure have been described and several authors have published their experiences and feedback to successfully accomplishing this procedure. Additionally, improved understanding of relevant soft tissue constraints and anatomic variants has provided improved margin of safety for patients. The procedure may be performed using specially-designed instruments and a fracture table, however many authors have also described equally efficacious performance using a regular table and standard arthroplasty tools. The capacity to utilize fluoroscopy intra-operatively for component positioning is a valuable asset to the approach and can be of particular benefit for surgeons gaining familiarity. Proper management of patient and limb positioning are vital to reducing risk of intra-operative complications. An understanding of its limitations and challenges are also critical to safe employment. This review summarizes the key features of the direct anterior approach for total hip arthroplasty as an aid to improving the understanding of this important and effective method for modern hip replacement surgeons. PMID:26807354

The direct anterior approach to the hip has been suggested to have several advantages compared to previously popular approaches through its use of an intra-muscular and intra-nervous interval between the tensor fasciae latae and sartorius muscles. Recent increased interest in tissue-sparing and minimally-invasive arthroplasty has given rise to a sharp increase in the utilization of direct anterior total hip arthroplasty. A number of variations of the procedure have been described and several authors have published their experiences and feedback to successfully accomplishing this procedure. Additionally, improved understanding of relevant soft tissue constraints and anatomic variants has provided improved margin of safety for patients. The procedure may be performed using specially-designed instruments and a fracture table, however many authors have also described equally efficacious performance using a regular table and standard arthroplasty tools. The capacity to utilize fluoroscopy intra-operatively for component positioning is a valuable asset to the approach and can be of particular benefit for surgeons gaining familiarity. Proper management of patient and limb positioning are vital to reducing risk of intra-operative complications. An understanding of its limitations and challenges are also critical to safe employment. This review summarizes the key features of the direct anterior approach for total hip arthroplasty as an aid to improving the understanding of this important and effective method for modern hip replacement surgeons. PMID:26807354

The concept of femoroacetabular impingement (FAI) has, in a relatively short time, come to the forefront of orthopedic imaging. In just a few short years MRI findings that were in the past ascribed to degenerative change, normal variation, or other pathologies must now be described and included in radiology reports, as they have been shown, or are suspected to be related to, FAI. Crucial questions have come up in this time, including: what is the relationship of bony morphology to subsequent cartilage and labral damage, and most importantly, how is this morphology related to the development of osteoarthritis? In this review we attempt to place a historical perspective on the controversy, provide guidelines for interpretation of MRI examinations of patients with suspected FAI, and offer a glimpse into the future of MRI of this complex condition. PMID:25155435

The concept of femoroacetabular impingement (FAI) has, in a relatively short time, come to the forefront of orthopedic imaging. In just a few short years MRI findings that were in the past ascribed to degenerative change, normal variation, or other pathologies must now be described and included in radiology reports, as they have been shown, or are suspected to be related to, FAI. Crucial questions have come up in this time, including: what is the relationship of bony morphology to subsequent cartilage and labral damage, and most importantly, how is this morphology related to the development of osteoarthritis? In this review, we attempt to place a historical perspective on the controversy, provide guidelines for interpretation of MRI examinations of patients with suspected FAI, and offer a glimpse into the future of MRI of this complex condition. PMID:25155435

Background: Excessive pelvic tilt may be one of the factors leading to instability in total hip arthroplasty (THA), even when the acetabular cup is placed properly. To our knowledge, only a few studies have described late anterior dislocation due to posterior pelvic tilt. We present 3 cases with late anterior dislocations possibly due to posterior pelvic tilt. Cases Presentations: Case-1: An 84-years-old woman fell and presented with an anterior dislocation 12-years after THA. Her pelvis had tilted to approximately 30° posteriorly in a supine position. After conservative treatment, she presented with 10 recurrent anterior dislocations. She had thoracolumbar kyphosis due to multiple compression fractures. Revision with anterior placement of an elevated liner and a 32-mm head corrected the dislocation, and no further dislocations occurred. Case-2: A 78-years-old woman fell and presented with an anterior dislocation 4-years after THA. Her posterior pelvic tilt had increased 23° due to a lumbar compression fracture. Revision by decreasing the cup anteversion was performed, but recurrent posterior dislocations occurred. Owing to her worsened general condition, further treatment was abandoned. Case-3: A 79-years-old woman twisted her body and presented an anterior dislocation 3-years after THA. After manual reduction and conservative treatment, the dislocation recurred. Her posterior pelvic tilt had increased 16°. Conclusion: Although minor trauma triggered the anterior instability in these patients, the underlying pathomechanism existed in the progressive pelvic posterior tilt due to thoracolumbar kyphosis. As longer life expectancy as well as implant survivorship is predicted, attention must be paid to the change of pelvic tilt in elderly patients. PMID:27398108

Background: Symptomatic femoroacetabular impingement (FAI) is currently corrected by surgery. However, it is possible that nonsurgical treatment could resolve symptomatic FAI in some patients; thus, uncertainty about the necessity of surgical treatment exists. The current equipoise concerning FAI treatment presents an opportunity to conduct a randomized controlled trial (RCT) of surgical and nonsurgical treatment options. Given the unique challenge of adequate patient enrollment in RCTs, it is important that a preliminary study is done to appraise the feasibility of conducting an RCT. Purpose: To estimate enrollment rates of a planned future RCT to compare surgical and nonsurgical treatments for symptomatic FAI and to identify factors associated with patients’ willingness to participate in the randomized trial. Study Design: Cross-sectional study; Level of evidence, 4. Methods: Patients diagnosed with FAI at 2 orthopaedic centers were presented with a hypothetical randomized trial comparing 2 treatment options for FAI. All patients completed forms providing information regarding their willingness to participate and treatment preferences. Results: A total of 75 patients participated in the study: 53 and 22 from 2 centers, respectively. Twenty-eight percent indicated absolute willingness to participate in the trial, 40% were probably willing or unsure, and 32% were definitely not willing; 18.7% had a strong preference for surgery while 2.7% strongly preferred nonsurgical treatment. The majority (78.6%) had no strong preference for either treatment arm. There were correlations between treatment preferences and willingness to participate. Patients with a strong treatment preference and/or a preference for surgery were less likely to be willing to participate. Conclusion: The study findings suggest that sufficient patient accrual for a randomized trial of FAI treatment is currently feasible while equipoise still exists among patients and surgeons. PMID:26673688

Edge-loading in patients with metal-on-metal resurfaced hips can cause high serum metal ion levels, the development of soft-tissue reactions local to the joint called pseudotumours and ultimately, failure of the implant. Primary edge-loading is where contact between the femoral and acetabular components occurs at the edge/rim of the acetabular component whereas impingement of the femoral neck on the acetabular component's edge causes secondary or contrecoup edge-loading. Although the relationship between the orientation of the acetabular component and primary edge-loading has been identified, the contribution of acetabular component orientation to impingement and secondary edge-loading is less clear. Our aim was to estimate the optimal acetabular component orientation for 16 metal-on-metal hip resurfacing arthroplasty (MoMHRA) subjects with known serum metal ion levels. Data from motion analysis, subject-specific musculoskeletal modelling and Computed Tomography (CT) measurements were used to calculate the dynamic contact patch to rim (CPR) distance and impingement risk for 3416 different acetabular component orientations during gait, sit-to-stand, stair descent and static standing. For each subject, safe zones free from impingement and edge-loading (CPR <10%) were defined and, consequently, an optimal acetabular component orientation was determined (mean inclination 39.7° (SD 6.6°) mean anteversion 14.9° (SD 9.0°)). The results of this study suggest that the optimal acetabular component orientation can be determined from a patient's motion and anatomy. However, 'safe' zones of acetabular component orientation associated with reduced risk of dislocation and pseudotumour are also associated with a reduced risk of edge-loading and impingement. PMID:25482661

Sixteen different variables and 3 indices for the anterior border of 42 human hip bones from a Spanish skeletal collection were studied. Values for 15 of these variables and for the 3 indices are reported. We were unable to detect statistically significant differences between means relating to side in any of the variables and indices studied. Statistically significant differences were detected between means in relation to sex for 4 variables (distance from the anterior superior iliac spine to the pubic tubercle, distance from the anterior inferior iliac spine to the iliopubic eminence, distance from the anterior inferior iliac spine to the pubic tubercle, length of the notch between the anterior inferior iliac spine and the iliopubic eminence). These variables could be used for sex determination from the human hip bone or its fragments. PMID:1304579

We evaluated the quality of information available on the Internet regarding the direct anterior approach (DAA). The top 50 Web sites from three major search engines (Google, Yahoo!, and Bing) were tabulated utilizing the search term direct anteriorhip replacement. Of these, only 22% were authored by a hospital/university, while 60% were by a private physician/clinic. Most Web sites presented the DAA as "better" than other surgical approaches describing benefits, such as accelerated recovery though only 35% described risks of the approach. While only 39% of sites presented patient eligibility criteria, greater than 75% had the ability to make an appointment. Web sites regarding the DAA provide patients with a limited perspective and may be focused on attracting new patients, as opposed to accurately educating them. PMID:25697892

We present a retrospective review of the early results and complications in a series of 35 consecutive patients with 43 total hip arthroplasties performed through an anterior muscle sparing minimally invasive approach. We found the early complication rates and radiographic outcomes comparable to those reported from arthroplasties performed via traditional approaches. Complications included dislocation (2%), femur fracture (2%), greater trochanteric fracture (12%), postoperative periprosthetic intertrochanteric fracture (2%), femoral nerve palsy (5%), hematoma (2%), and postoperative iliopsoas avulsion (2%). Radiographic analysis revealed average cup anteversion of 19.6° ± 6.6, average cup abduction angle of 48.4° ± 7, stem varus of 0.9° ± 2, and a mean leg length discrepancy of 0.7 mm. The anterior approach to the hip is an attractive alternative to the more traditional approaches. Acceptable component placement with comparable complication rates is possible using a muscle sparing technique which may lead to faster overall recovery. PMID:24715984

Open anteriorhip dislocation is a rare condition and results from high‐energy trauma. Ten cases of open anterior dislocation have been described in the literature so far. Its rarity is due to the inherent stability of the joint, its deep position in the pelvis, with strong ligaments and bulky muscles around the articulation. Several factors influence the prognosis, such as the degree of compounding, the associated soft tissue injuries, the age of the patient and, mainly, the delay in reduction. The main complications are: arthrosis of the hip, with incidence of 50% of cases, when associated with fractures of the femoral head; and osteonecrosis of the femoral head, with incidence between 1.7 and 40% (in closed anterior dislocation). Because of the rarity and the potential disability of this lesion, we report a case in a 46‐year‐old man, involved in an automobile accident. The hip was reduced (anterior superior dislocation) in the first three hours of the trauma. The patient was kept non‐weight bearing until sixth week, with complete weight bearing after 10th week. After one year follow‐up, the functional result was poor (Harris Hip Score: 52), probably because of the associated labral tear, but without signs of osteonecrosis of the femoral head in magnetic resonance imaging. PMID:26229781

Hip pain is a common and disabling condition that affects patients of all ages. The differential diagnosis of hip pain is broad, presenting a diagnostic challenge. Patients often express that their hip pain is localized to one of three anatomic regions: the anteriorhip and groin, the posterior hip and buttock, or the lateral hip. Anteriorhip and groin pain is commonly associated with intra-articular pathology, such as osteoarthritis and hip labral tears. Posterior hip pain is associated with piriformis syndrome, sacroiliac joint dysfunction, lumbar radiculopathy, and less commonly ischiofemoral impingement and vascular claudication. Lateral hip pain occurs with greater trochanteric pain syndrome. Clinical examination tests, although helpful, are not highly sensitive or specific for most diagnoses; however, a rational approach to the hip examination can be used. Radiography should be performed if acute fracture, dislocations, or stress fractures are suspected. Initial plain radiography of the hip should include an anteroposterior view of the pelvis and frog-leg lateral view of the symptomatic hip. Magnetic resonance imaging should be performed if the history and plain radiograph results are not diagnostic. Magnetic resonance imaging is valuable for the detection of occult traumatic fractures, stress fractures, and osteonecrosis of the femoral head. Magnetic resonance arthrography is the diagnostic test of choice for labral tears. PMID:24444505

Arthroscopic resection of the anterior inferior iliac spine (AIIS) for subspine impingement has become a relatively common procedure. The AIIS is the origin of the direct head of rectus femoris (dhRF). Previous studies have reported that removal of the contributing portion of the AIIS causing impingement is unlikely to weaken the attachment of the dhRF. The purpose of this article is to report a case of avulsion of the dhRF, following revision hip arthroscopy for the treatment of subspine impingement. A 23-year-old professional footballer underwent revision left hip arthroscopy for the treatment of subspine impingement. 5-mm of bone was resected inferior to the AIIS. Two-weeks post-operatively, he presented with sudden onset, severe left anterior thigh pain following a fall and hyperextension of his left hip. The patient felt a pop over the anterior aspect of his hip. He noticed immediate swelling, severe pain and stiffness. Examination revealed diffuse swelling, 4/5-power on straight-leg-raise, focal tenderness over the AIIS but no palpable gap. MRI confirmed the clinical suspicion of a dhRF avulsion. Given the minimal loss of power and the lack of significant retraction, the patient was treated conservatively. He was instructed to avoid excessive hip extension. He returned to full participation at 3-months. This article highlights a case of avulsion of the dhRF due to a hyperextension injury of the hip following arthroscopic resection of subspinal impingement, a previously unreported complication. Resection of soft and bone from the AIIS may weaken the insertion of the dhRF. Care should be taken during post-operative rehabilitation to avoid trauma and excessive forces on the dhRF tendon, which may lead to rupture. Rehabilitation should be focused on range of motion of the hip. PMID:27026819

Arthroscopic resection of the anterior inferior iliac spine (AIIS) for subspine impingement has become a relatively common procedure. The AIIS is the origin of the direct head of rectus femoris (dhRF). Previous studies have reported that removal of the contributing portion of the AIIS causing impingement is unlikely to weaken the attachment of the dhRF. The purpose of this article is to report a case of avulsion of the dhRF, following revision hip arthroscopy for the treatment of subspine impingement. A 23-year-old professional footballer underwent revision left hip arthroscopy for the treatment of subspine impingement. 5-mm of bone was resected inferior to the AIIS. Two-weeks post-operatively, he presented with sudden onset, severe left anterior thigh pain following a fall and hyperextension of his left hip. The patient felt a pop over the anterior aspect of his hip. He noticed immediate swelling, severe pain and stiffness. Examination revealed diffuse swelling, 4/5-power on straight-leg-raise, focal tenderness over the AIIS but no palpable gap. MRI confirmed the clinical suspicion of a dhRF avulsion. Given the minimal loss of power and the lack of significant retraction, the patient was treated conservatively. He was instructed to avoid excessive hip extension. He returned to full participation at 3-months. This article highlights a case of avulsion of the dhRF due to a hyperextension injury of the hip following arthroscopic resection of subspinal impingement, a previously unreported complication. Resection of soft and bone from the AIIS may weaken the insertion of the dhRF. Care should be taken during post-operative rehabilitation to avoid trauma and excessive forces on the dhRF tendon, which may lead to rupture. Rehabilitation should be focused on range of motion of the hip. PMID:27026819

The aim of this study was to investigate the safety of one-stage bilateral open reduction using the anterior approach in the treatment of patients with bilateral Tönnis Type III and IV Developmental Dysplasia of the Hip (DDH). Forty-six patients were retrospectively evaluated. Thirty-eight were female, eight were male. The mean age was 16.63 (11-29) months. The mean follow-up period was 27.18 (12-65) months. The mean hospitalization period after surgery was 1.91 (1-5) days. The mean pre-operative hematocrit level was 35.14% (28.1-44.1) and the mean pre-operative hemoglobin level was 11.75 g/dl (9.3-13.6). The mean post-operative hematocrit level was 32.54% (26.7-40.4) and the mean post-operative hemoglobin level was 10.80 g/dl (8.78-12.3). None of the patients required blood transfusion. The mean anesthesia duration was 133.30 (95-180) minutes, and the mean operation duration was 107.58 (70-145) minutes. According to the modified scoring system by Trevor et al, excellent results were obtained in 66 hips of 46 patients (71.8%), and good results were obtained in 26 hips (28.2%). Twenty two hips (23.91%), which developed acetabular dysplasia in the follow-up period required a secondary acetabular intervention. According to the Kalamchi and MacEwen classification, Type I avascular necrosis developed in ten hips, Type II in one hip, and Type IV in two hips. One-stage bilateral open reduction using the anterior iliofemoral approach in Tönnis Type III and IV DDH at walking age is a safe, time-saving treatment method that shortens the hospitalization and immobilization periods. PMID:25090794

Context: In active individuals with femoroacetabular impingement (FAI), the resultant reduction in functional range of motion leads to high impaction loads at terminal ranges. These increased forces result in compensatory effects on bony and soft tissue structures within the hip joint and hemipelvis. An algorithm is useful in evaluating athletes with pre-arthritic, mechanical hip pain and associated compensatory disorders. Evidence Acquisition: A literature search was performed by a review of PubMed articles published from 1976 to 2013. Level of Evidence: Level 4. Results: Increased stresses across the bony hemipelvis result when athletes with FAI attempt to achieve supraphysiologic, terminal ranges of motion (ROM) through the hip joint required for athletic competition. This can manifest as pain within the pubic joint (osteitis pubis), sacroiliac joint, and lumbosacral spine. Subclinical posterior hip instability may result when attempts to increase hip flexion and internal rotation are not compensated for by increased motion through the hemipelvis. Prominence of the anterior inferior iliac spine (AIIS) at the level of the acetabular rim can result in impingement of the anteriorhip joint capsule or iliocapsularis muscle origin against the femoral head-neck junction, resulting in a distinct form of mechanical hipimpingement (AIIS subspine impingement). Iliopsoas impingement (IPI) has also been described as an etiology for anteriorhip pain. IPI results in a typical 3-o’clock labral tear as well as an inflamed capsule in close proximity to the overlying iliopsoas tendon. Injury in athletic pubalgia occurs during high-energy twisting activities in which abnormal hip ROM and resultant pelvic motion lead to shearing across the pubic symphysis. Conclusion: Failure to recognize and address concomitant compensatory injury patterns associated with intra-articular hip pathology can result in significant disability and persistent symptoms in athletes with pre

ABSTRACT Background Generalized joint laxity is more prevalent in women than men and may lead to poorer post-operative outcomes in select orthopedic populations. There are no studies examining peri-operative function in patients with generalized joint laxity (GJL) and femoroacetabular impingement (FAI). Purpose The purpose of this study was to determine the difference in perceived function and quality of life as measured by the Hip Outcome Score ADL subscale (HOS-ADL), International Hip Outcomes Tool (iHOT-33) and the Short Form 12-Item Health Survey (SF-12) in women with and without GJL prior to and six months after undergoing hip arthroscopy for FAI. Study Design Cohort Study Methods Peri-operative data were collected from women with FAI from November 2011-September 2014. Lax subjects were women with laxity scores ≥4/9 on the Beighton and Horan Joint Mobility Index; Nonlax subjects were women with laxity scores <4/9. Functional outcomes were evaluated using the HOS-ADL, iHOT-33, PCS-12, and the MCS-12 pre-operatively and at 6 months post-operatively. Change scores (post-score – pre-score) were calculated for each outcome measure and compared between groups, along with pre-operative and post-operative means, using Mann-Whitney U tests. Results 166 women met the inclusion criteria: Nonlax (n = 131), Lax (n = 35). There were no statistically significant differences between groups in pre-operative functional outcomes (all p > .05). Additionally, there were no statistically significant differences between groups in post-operative means or change scores, respectively, for HOS-ADL (p = .696, .358), iHOT-33 (p = .550, .705), PCS-12 (p = .713, .191), and MCS-12 (p = .751, .082). Laxity score was not associated with any post-operative functional outcome score or change score (all p > .05). Conclusion Women with and without generalized joint laxity do not appear to report differences in hip function in the 6-month peri-operative period before and after hip

BACKGROUND Femoroacetabular impingement (FAI) is a syndrome of hip or groin pain associated with shape abnormalities of the hip joint. Treatments include arthroscopic surgery and conservative care. This study explored the feasibility of a randomised controlled trial to compare these treatments. OBJECTIVES The objectives of this study were to estimate the number of patients available for a full randomised controlled trial (RCT); to explore clinician and patient willingness to participate in such a RCT; to develop consensus on eligibility criteria, surgical and best conservative care protocols; to examine possible outcome measures and estimate the sample size for a full RCT; and to develop trial procedures and estimate recruitment and follow-up rates. METHODS Pre-pilot work: we surveyed all UK NHS hospital trusts (n = 197) to identify all FAI surgeons and to estimate how much arthroscopic FAI surgery they performed. We interviewed a purposive sample of 18 patients, 36 physiotherapists, 18 surgeons and two sports physicians to explore attitudes towards a RCT and used consensus-building methods among them to develop treatment protocols and patient information. Pilot RCT: we performed a pilot RCT in 10 hospital trusts. Patients were randomised to receive either hip arthroscopy or best conservative care and then followed up at 3, 6 and 12 months using patient-reported questionnaires for hip pain and function, activity level, quality of life, and a resource-use questionnaire. Qualitative recruitment intervention: we performed semistructured interviews with all researchers and clinicians involved in the pilot RCT in eight hospital trusts and recorded and analysed diagnostic and recruitment consultations with eligible patients. RESULTS We identified 120 surgeons who reported treating at least 1908 patients with FAI by hip arthroscopy in the NHS in the financial year 2011/12. There were 34 hospital trusts that performed ≥ 20 arthroscopic FAI operations in the year

The concept of psoas impingement secondary to a tight or inflamed iliopsoas tendon causing impingement of the anterior labrum during hip extension has been suggested. The purpose of this study was to assess the relationship between the lesser trochanteric version (LTV) in symptomatic patients with psoas impingement as compared with asymptomatic hips. The femoral neck version (FNV) and LTV were evaluated on axial magnetic resonance imaging, as well as the angle between LTV and FNV. Data from 12 symptomatic patients and 250 asymptomatic patients were analysed. The mean, range and standard deviations were calculated. Independent t-tests were used to determine differences between groups. The lesser trochanteric retroversion was significantly increased in patients with psoas impingement as compared with asymptomatic hips (−31.1° SD ± 6.5 versus −24.2° ± 11.5, P 0.05) and the angle between FNV and LTV (40.2° ± 9.7 versus 38.3° ± 9.6, P > 0.05) were not significantly different between groups. In conclusion, the lesser trochanteric retroversion is significantly increased in patients with psoas impingement as compared with asymptomatic hips. PMID:27011834

The impingement syndrome is a common disorder of the shoulder girdle. The causes for this syndrome may be anatomic changes in the coracoacromial arch, also within the ultrastructural regions, on the one hand, or changes in the biomechanics which have developed for various reasons, on the other. Diagnosis is based on roentgenograms using the appropriate technique. In large-scale-studies, sonography has proved to be an extremely sensitive screening method for differential diagnosis of rupture of the rotator cuff. Magnetic resonance imaging might gain in value in the diagnosis of impingement as regards differential diagnosis of rupture of the rotator cuff because this technique--when employed appropriately--allows exact viewing of the soft tissue and the anterior part of the acromion. In the majority of cases conservative treatment is the method of choice. Methods of treatment are sonography, galvanization, and application of heat. Physiotherapy should not be initiated until pain relief has been achieved by other measures. Infiltration therapy is of considerable value in the management of pain due to impingement. Application of cortisone into the subacromial space must also be considered critically. As regards conservative therapy, only few evidence-based publications provide information on the effectiveness of different treatment regimens. Surgical therapy is only indicated in cases of pain resistant to the conservative therapy for a certain period. Furthermore, only an outlet impingement can be treated successfully by surgical decompression. The surgeon decides on the surgical method--open surgery or arthroscopy. Of course, arthroscopic methods are less invasive; however, up to now the superiority of one of the surgical methods over the other could not yet be proven by mid-term clinical results. Other surgical methods such as wedge osteotomy in the region of the spina scapulae are still in the experimental stage. By surgical and conservatives methods, good and even

Studies suggest that total hip arthroplasty (THA) performed through direct anterior (DA) approach has better functional outcomes than other surgical approaches. The immediate to very early outcomes of DA THA are not known. A prospective, randomized study examined the very early outcome of THA performed through DA versus direct lateral approach. The functional outcomes on day 1, day 2, week 6, week 12, 6 months, and 1 year were measured. Patients receiving DA THA had significantly higher functional scores during the early period following surgery. The difference in functional scores leveled out at 6 months. PMID:27241374

Objectives: Anatomic femoral tunnel placement for single-bundle ACL reconstruction is now well accepted. The ideal location for the tibial tunnel, however, has not been studied extensively. A wide range of anterior to posterior (A-P) tibial tunnel locations are considered acceptable. Biomechanical data suggests that the anterior fibers of the native ACL are more functional. Similarly, ACL grafts placed more anteriorly in the footprint have resulted in improved clinical results in at least one study. However, the concern for intercondylar roof impingement has tempered enthusiasm for a more anterior tibial tunnel placement. Investigations by Howell and others on roof impingement have focused only on the transtibial technique. Our study seeks to characterize intercondylar roof impingement in a 3-D cadaveric model with both transtibial and independent femoral tunnel drilling techniques in the setting of an anteriorly positioned tibial tunnel. Methods: Twelve fresh frozen cadaver knees (six matched pairs) were randomized to either a transtibial or an independent femoral (IF) drilling technique. Tibial guide pins were placed in the anterior half of the ACL tibial footprint following arthroscopic debridement of the native ACL. A fluoroscopic calculation of the tibial guide pin location using the technique described by Staubli was used to ensure a relatively anterior position of the tibial tunnel (Staubli < 35). All efforts were made to place the femoral tunnel anatomically in the center of the footprint. An 8 mm Gore-Tex smoother was passed into the knee to function as a radiopaque surrogate graft, and the knees then underwent computed tomography in maximal extension. Graft-visualized 3D-CT reformatting was used to evaluate for roof impingement by analyzing the Impingement Review Index (IRI) as described by Iriuchishima. Tunnel morphology, knee flexion, and intra-articular graft angles were also recorded. Results: Two grafts (2/6, 33.3 %) in the TT group impinged upon the

The aim of the present study was to determine the relationship between knee pain severity and function with the frontal plane projection angle (FPPA) and trunk and hip peak torque (PT) in women with patellofemoral pain (PFPS). Twenty-two women with PFPS were assessed. Knee pain severity (KPS) was assessed with an 11-point visual analog scale and function with an Anterior Knee Pain Scale. The FPPA was recorded with a digital camera. PT of extensors, abductors, and the lateral rotators of hip and lateral core stability were measured with a handheld dynamometer. FPPA was the only predictor for the KPS. Regarding predictors of function, PT of lateral core stability and the extensor and abductor of the hip explained 41.4% of the function. Increase in FPPA was associated with greater KPS, and the lowest PT of lateral core stability, hip abductors, and extensors was associated with lower function in women with PFPS. PMID:26118529

Hip instability is becoming a more commonly recognized source of pain and disability in patients. Traumatic causes of hip instability are often clear. Appropriate treatment includes immediate reduction, early surgery for acetabular rim fractures greater than 25% or incarcerated fragments in the joint, and close follow-up to monitor for avascular necrosis. Late surgical intervention may be necessary for residual symptomatic hip instability. Atraumatic causes of hip instability include repetitive external rotation with axial loading, generalized ligamentous laxity, and collagen disorders like Ehlers-Danlos. Symptoms caused by atraumatic hip instability often have an insidious onset. Patients may have a wide array of hip symptoms while demonstrating only subtle findings suggestive of capsular laxity. Traction views of the affected hip can be helpful in diagnosing hip instability. Open and arthroscopic techniques can be used to treat capsular laxity. We describe an arthroscopic anteriorhip capsular plication using a suture technique. PMID:20473129

Background: Osteoarthritis of the hip is five to ten times more common in white people than in Chinese people. Little is known about the true prevalence of femoroacetabular impingement or its role in the development of osteoarthritis in the Chinese population. A cross-sectional study of both white and Chinese asymptomatic individuals was conducted to compare the prevalences of radiographic features posing a risk for femoroacetabular impingement in the two groups. It was hypothesized that that there would be proportional differences in hip anatomy between the white and Asian populations. Methods: Pelvic computed tomography scans of 201 subjects (ninety-nine white Belgians and 102 Chinese; 105 men and ninety-six women) without hip pain who were eighteen to forty years of age were assessed. The original axial images were reformatted to three-dimensional pelvic models simulating standardized radiographic views. Ten radiographic parameters predisposing to femoroacetabular impingement were measured: alpha angle, anterior offset ratio, and caput-collum-diaphyseal angle on the femoral side and crossover sign, ischial spine projection, acetabular anteversion angle, center-edge angle, acetabular angle of Sharp, Tönnis angle, and anterior acetabular head index on the acetabular side. Results: The white subjects had a less spherical femoral head than the Chinese subjects (average alpha angle, 56° compared with 50°; p < 0.001). The Chinese subjects had less lateral acetabular coverage than the white subjects, with average center-edge angles of 35° and 39° (p < 0.001) and acetabular angles of Sharp of 38° and 36° (p < 0.001), respectively. A shallower acetabular configuration was predominantly present in Chinese women. Conclusions: Significant differences in hip anatomy were demonstrated between young asymptomatic Chinese and white subjects. However, the absolute size of the observed differences appears to contrast with the reported low prevalence of femoroacetabular

Manual load carriage continues to be a major contributor of musculoskeletal injury. This study investigates the physiological and subjective effects of an on-hip load-carrying belt (HLCB) during bimanual anterior load carriage. Fifteen healthy male participants walked on a level ground treadmill at 4.5 km/h for 5 min carrying 5, 10 and 15 kg loads with hands and arms in front of the body, with and without using the HLCB (WD and ND). Heart rate, normalized oxygen uptake, minute ventilation and, central and peripheral ratings of perceived exertion were the dependent variables. The mean heart rate, normalized oxygen uptake, minute ventilation and peripheral rating of perceived exertion increased significantly with load under both WD and ND conditions. At a load of 15 kg, the mean heart rate, normalized oxygen uptake, minute ventilation and peripheral rating of perceived exertion were significantly lower by 6.6%, 8.0%, 11.8% and 13.9% respectively in WD condition when compared to the ND condition. There was no significant difference between WD and ND conditions with 5 or 10 kg load. It can be concluded that the HLCB could reduce a person's physiological and peripheral perceptual responses when walking on a level ground treadmill at 4.5 km/h with a load of 15 kg. Using a HLCB or similar device is therefore recommended for bimanual anterior load carriage for loads of 15 kg or probably larger. PMID:26995043

The purposes of this study were to compare lower-extremity kinematics during a 45° and 90° cutting maneuver and to examine the relationships between lower-extremity rotations during these maneuvers. The hypotheses tested were that greater internal hip and knee rotation angles would be observed during the cutting maneuver at a 90° angle (90° cut) compared with the maneuver performed at a 45° angle (45° cut) and that the increased internal hip and knee rotation would be related to increased knee abduction measures. Nineteen athletes from women’s soccer teams (17.6 ± 2.1 yr, 165.6 ± 8.2 cm, 60.2 ± 5.6 kg) were instructed to jump across a line and cut at the appropriate angle (either 45° or 90° side-step cut) and in the appropriate direction. Lower-extremity kinematic measures were taken at peak force during the stance phase. Hip internal rotation and knee internal rotation (p = 0.008) were increased during the 90° cut compared with the 45° cut. Mean hip flexion (p < 0.001) was also greater in the 90° cut. The only significant predictor of knee abduction during both tasks was hip adduction (R = 0.49). The findings indicate that the mechanisms underlying increased knee abduction measures in athletic women during cutting tasks were primarily coronal plane motions at the hip. Trunk and hip focused strength neuromuscular training may improve the ability of athletic women to increase control of lower-extremity alignment. Therefore, these women may decrease dangerous knee loads that result from increased hip adduction during dynamic tasks, thus decreasing anterior cruciate ligament injury risk. PMID:19826304

The purposes of this study were to compare lower-extremity kinematics during a 45 degrees and 90 degrees cutting maneuver and to examine the relationships between lower-extremity rotations during these maneuvers. The hypotheses tested were that greater internal hip and knee rotation angles would be observed during the cutting maneuver at a 90 degrees angle (90 degrees cut) compared with the maneuver performed at a 45 degrees angle (45 degrees cut) and that the increased internal hip and knee rotation would be related to increased knee abduction measures. Nineteen athletes from women's soccer teams (17.6 +/- 2.1 yr, 165.6 +/- 8.2 cm, 60.2 +/- 5.6 kg) were instructed to jump across a line and cut at the appropriate angle (either 45 degrees or 90 degrees side-step cut) and in the appropriate direction. Lower-extremity kinematic measures were taken at peak force during the stance phase. Hip internal rotation and knee internal rotation (p = 0.008) were increased during the 90 degrees cut compared with the 45 degrees cut. Mean hip flexion (p < 0.001) was also greater in the 90 degrees cut. The only significant predictor of knee abduction during both tasks was hip adduction (R = 0.49). The findings indicate that the mechanisms underlying increased knee abduction measures in athletic women during cutting tasks were primarily coronal plane motions at the hip. Trunk and hip focused strength neuromuscular training may improve the ability of athletic women to increase control of lower-extremity alignment. Therefore, these women may decrease dangerous knee loads that result from increased hip adduction during dynamic tasks, thus decreasing anterior cruciate ligament injury risk. PMID:19826304

Objective: The purpose of this study is to evaluate the short-term follow-up results of arthroscopic treatment of femoroacetabular impingement. Our hypothesis is that arthroscopic treatment results are favorable. Methods: Between August 2003 and August 2007, 28 hips had femoroacetabular impingement treated by hip arthroscopy. The mean age was 34 years, with mean follow-up period of 27 months. Clinical results were graded with the modified Harris hip score, which was measured pre- and postoperatively. Patients had also their internal rotation analyzed. These parameters were calculated by using Wilcoxon's t test for analysis of nonparametric paired samples performed. Results: The mean preoperative Harris Hip Score was 54.2, improving to 94.8 postoperatively (p<0,001). The mean increase was 37.5 points. We had 4 good results (15%) and 24 excellent results (85%). Preoperatively, the patients had a mean internal rotation of 17°, and, postoperatively, 36°. The average internal rotation increase was 19° (p<0,001). Conclusions: The arthroscopic treatment of femoroacetabular impingement presents satisfactory results. PMID:27004177

Objective The purpose of this case report is to describe a patient with femoroacetabular impingement (FAI) who was initially misdiagnosed and treated for a hip flexor strain. Clinical Features A 36-year-old male patient presented with insidious onset of progressive anterior right hip and groin pain of 7 years' duration. He was diagnosed with a right-sided hip flexor muscle strain and was discharged from care 1 month later. The patient then returned to the office 8 years later for treatment of unrelated lower back pain. This time, the doctor of chiropractic learned that the patient was misdiagnosed years before. The patient's past radiographs in fact revealed FAI, including severe hip joint osteoarthritis on the right and mild osteoarthritis on the left. As a result, the patient had undergone right hip joint replacement surgery. Recent radiographs also revealed FAI in the contralateral hip. Intervention and Outcome After investigating for FAI, the doctor of chiropractic was able to identify through symptomatology, history, physical examination, and radiographs the presence of FAI in the patient's left hip. An “active surveillance” approach is being taken. Conclusion This case illustrates the importance of an increasing awareness of FAI, as doctors of chiropractic are frequently the primary contact for patients with this condition. PMID:26793042

This article presents a brief review of pincer impingement pathomechanics and the current methods of diagnosis, followed by a discussion of many of the current controversies in addressing pincer morphology. These controversies include controversial surgical indications such as global acetabular retroversion and the role of prophylactic surgery, controversial surgical techniques to address the acetabular labrum, as well as the best methods for intraoperative evaluation of the arthroscopic acetabuloplasty. PMID:27343393

Hip arthroscopy is a safe method for treating a variety of pathological conditions that were unknown until a decade ago. Femoroacetabular impingement is the commonest of these pathological conditions and the one with the best results when treated early on. The instruments and surgical technique for hip arthroscopy continue to evolve. New indications for hip arthroscopy has been studied as the ligamentum teres injuries, capsular repair in instabilities, dissection of the sciatic nerve and repair of gluteal muscles tears (injuries to the hip rotator cuff), although still with debatable reproducibility. The complication rate is low, and ever-better results with fewer complications should be expected with the progression of the learning curve. PMID:26229924

The purpose of this study was to assess if delayed gadolinium MRI of cartilage using postcontrast T(1) (T(1Gd)) is sufficient for evaluating cartilage damage in femoroacetabular impingement without using noncontrast values (T(10)). T(1Gd) and DeltaR(1) (1/T(1Gd) - 1/T(10)) that include noncontrast T(1) measurements were studied in two grades of osteoarthritis and in a control group of asymptomatic young-adult volunteers. Differences between T(1Gd) and DeltaR(1) values for femoroacetabular impingement patients and volunteers were compared. There was a very high correlation between T(1Gd) and DeltaR(1) in all study groups. In the study cohort with Tonnis grade 0, correlation (r) was -0.95 and -0.89 with Tonnis grade 1 and -0.88 in asymptomatic volunteers, being statistically significant (P < 0.001) for all groups. For both T(1Gd) and DeltaR(1), a statistically significant difference was noted between patients and control group. Significant difference was also noted for both T(1Gd) and DeltaR(1) between the patients with Tonnis grade 0 osteoarthritis and those with grade 1 changes. Our results prove a linear correlation between T(1Gd) and DeltaR(1), suggesting that T(1Gd) assessment is sufficient for the clinical utility of delayed gadolinium MRI of cartilage in this setting and additional time-consuming T(10) evaluation may not be needed. PMID:19859935

We have evaluated in vitro the accuracy of percutaneous and ultrasound registration as measured in terms of errors in rotation and version relative to the bony anterior pelvic plane in computer-assisted total hip replacement, and analysed the intra- and inter-observer reliability of manual or ultrasound registration. Four clinicians were asked to perform registration of the landmarks of the anterior pelvic plane on two cadavers. Registration was performed under four different conditions of acquisition. Errors in rotation were not significant. Version errors were significant with percutaneous methods (16.2 degrees; p < 0.001 and 19.25 degrees with surgical draping; p < 0.001), but not with the ultrasound acquisition (6.2 degrees, p = 0.13). Intra-observer repeatability was achieved for all the methods. Inter-observer analysis showed acceptable agreement in the sagittal but not in the frontal plane. Ultrasound acquisition of the anterior pelvic plane was more reliable in vitro than the cutaneous digitisation currently used. PMID:18256101

Femoroacetabular impingement (FAI) is a clinical syndrome resulting from abnormal hip joint morphology and is a common cause of hip pain in young adults. FAI has been posited as a precursor to hip osteoarthritis (OA); however, conflicting evidence exists and the true natural history of the disease is unclear. The purpose of this article is to review the current understanding of how FAI damages the hip joint by highlighting its pathomechanics and etiology. We then review the current evidence relating FAI to OA. Lastly, we will discuss the potential of hip preservation surgery to alter the natural history of FAI, reduce the risk of developing OA and the need for future arthroplasty. PMID:26636088

Context: Dance, gymnastics, figure skating, and competitive cheerleading require a high degree of hip range of motion. Athletes who participate in these sports use their hips in a mechanically complex manner. Evidence Acquisition: A search of the entire PubMed database (through December 2013) and additional searches of the reference lists of pertinent articles. Study Design: Systematic review. Level of Evidence: Level 3. Results: Whether innate or acquired, dancers and gymnasts have some hypermobility that allows their hips to be placed in potentially impinging or unstable positions required for their given activity. Such extremes of motion can result in both intra-articular and extra-articular impingement as well as compensatory osseous and muscular pathology. In addition, dancers and gymnasts are susceptible to impingement-induced instability. Dancers with innate generalized hyperlaxity are at increased risk of injury because of their activities and may require longer recovery times to return to play. Both nonoperative and operative treatments (arthroscopic and open) have an important role in returning flexibility athletes to their preoperative levels of sport and dance. Conclusion: Because of the extreme hip motion required and the compensatory soft tissue laxity in dancers and gymnasts, these athletes may develop instability, impingement, or combinations of both. This frequently occurs in the setting of subtle pathoanatomy or in patients with normal bony anatomy. With appropriate surgical indications and the correct operative technique, the treating surgeon can anticipate high levels of return to play for the gymnast and dancer with hip pain. PMID:26137181

Labral tears in the hip may cause painful clicking or locking of the hip, reduced range of motion, and disruption to sports and daily activities. The acetabular labrum aids stabilization of the hip joint, particularly during hip motion. The fibrocartilaginous structure extends the acetabular rim and provides a suction seal around the femoroacetabular interface. Treatment options for labral tears include debridement, repair, and reconstruction. Repair of the labrum has been shown to have better results than debridement. Labral refixation is achieved with sutures anchored into the acetabular rim. The acetabular rim is trimmed either to correct pincer impingement or to provide a bleeding bed to improve healing. Labral repair has shown excellent short-term to midterm outcomes and allows patients to return to activities and sports. Arthroscopic rim trimming and labral refixation comprise an effective treatment for labral tears with an underlying diagnosis of femoroacetabular impingement and are supported by the peer-reviewed literature. PMID:23875153

This study aimed to evaluate the usefulness of dynamic radiography using a dynamic flat-panel detector (FPD) system after hip resurfacing arthroplasty (HRA). A total of 32 hips of 26 patients who underwent HRA were included. Sequential images of active abduction in the supine position and flexion in the 45° semilateral position were obtained using the FPD system. We examined the imaging findings of impingement between the acetabular component and femoral neck with cooperative motion at maximal exercise. Moreover, the central component coordinate of the acetabulum and femoral head sides was measured. For abduction motion, impingement was detected in two (6.3 %) hips between the superior portion of the femoral neck and acetabular component. For flexion motion, impingement was detected in 19 (59.4 %) hips. There were no findings of subluxation between the acetabular component and femoral neck after impingement, but cooperative motion of lumbar and pelvic flexion was observed. There was no significant difference in the center-to-center distance regardless of the presence or absence of impingement. Detailed postoperative kinematics of the hips after HRA showed that the proposed dynamic FPD system could reveal acquired impingement and cooperative motion as dynamic images and possibly reveal findings that would be unobservable using static images. PMID:27207072

Developmental dysplasia of the hip is often diagnosed in infancy, but less severe cases of acetabular dysplasia are being detected in young active adults. The purpose of this case report is to present a non-surgical intervention for a 31-year-old female with mild acetabular dysplasia and an anterior acetabular labral tear. The patient presented with right anteriorhip and groin pain, and she stood with the trunk swayed posterior to the pelvis (swayback posture). The hip pain was reproduced with the anteriorimpingement test. During gait, the patient maintained the swayback posture and reported 6/10 hip pain. Following correction of the patient’s posture, the patient’s pain rating was reduced to a 2/10 while walking. The patient was instructed to maintain the improved posture. At the 1 year follow-up, she demonstrated significantly improved posture in standing and walking. She had returned to recreational running and was generally pain-free. The patient demonstrated improvement on self-reported questionnaires for pain, function and activity. These findings suggest that alteration of posture can have an immediate and lasting effect on hip pain in persons with structural abnormality and labral pathology. PMID:25731688

This study describes specific complications noticed during the first unselected cases operated by anterior approach for THA in our hospital and specific adjustments that were applied on the procedure to prevent these complications. We retrospectively analysed the differences between 202 patients who were operated by a standardised approach and 248 patients who were operated after adjustments were implemented with the procedure. Injury to the lateral femoral cutaneous nerve (LFCN), fractures of the greater trochanter and dislocation were specific complications that were noticed with the initial technique.Prevalence of injury to the LFCN decreased from 7.9% to 0.8% (p<0.001), fractures of the greater trochanter decreased from 5.4% to 0.8% (p = 0.004) and the incidence of dislocation decreased from 4.5% to 1.6% (p = 0.074). PMID:25198300

Groin and hip injuries are seen in athletes who perform quick directional changes and cutting movements. Because forces generated through athletic performance are transferred through the hip, injuries to these areas may limit athletes with mild pain or lead to career-ending injuries. The anatomy of the hip and groin is complex and symptoms often overlap. This article discusses some athletic causes, but other medical conditions may be associated with hip and groin pain as well. Updates in evaluation and treatment are discussed for adductor strains, hip osteoarthritis, femoroacetabular impingement, sports hernia, osteitis pubis, and obturator nerve entrapment. PMID:23668647

Hip dysplasia and hip joint deformities in general are recognized as possible precursors of osteoarthritic development. Early and correct identification of hip dysplasia is important in order to offer timely joint preserving treatment. In the contemporary literature, several controversies exist, and some of these were the focus of this doctoral thesis. Categorized into subjects, the major findings and their possible importance are listed below. DIAGNOSTIC ASSESSMENT OF HIP DYSPLASIA: A multi-observer study quantified the variability of different methods for diagnostic assessment of hip dysplasia and osteoarthritis and resulted in general recommendations regarding diagnostic assessment of hip dysplasia. Pelvic tilt was shown to differ significantly between the supine and weight-bearing positions in patients with dysplastic hip joints. This is a finding that adds controversy to the application of neutral pelvic positioning during assessment of hip deformities because pelvic tilt affects the appearance of acetabular version. Weight-bearing assessment of acetabular version showed the presence of retroversion in 33% of dysplastic hips. The establishment of retroversion as a rather frequent entity in dysplastic hips is contradictory to the historical finding that hip dysplasia is characterized by insufficient anterior and lateral coverage. In general, the findings have important implications for orthopedic surgeons and radiologists dealing with diagnostic assessment of painful hips in young adults, and for surgeons planning and performing joint-preserving periacetabular osteotomies. ASSESSMENT OF ACETABULAR LABRAL TEARS IN HIP DYSPLASIA: The roles of ultrasound and clinical tests in acetabular labral tear diagnostics were established. After overcoming an initial learning curve, ultrasound investigation was highly reliable in diagnosing labral tears, whereas only a positive impingement or FABER test was reliable in identifying a labral tear. It seems that non-invasive and

Hip joint instability and impingement are the most common biomechanical risk factors that put the hip joint at risk to develop premature osteoarthritis. Several surgical procedures like periacetabular osteotomy for hip dysplasia or hip arthroscopy or safe surgical hip dislocation for femoroacetabular impingement aim at restoring the hip anatomy. However, the success of joint preserving surgical procedures is limited by the amount of pre-existing cartilage damage. Biochemically sensitive MRI techniques like delayed Gadolinium Enhanced MRI of Cartilage (dGEMRIC) might help to monitor the effect of surgical or non-surgical procedures in the effort to halt or even reverse joint damage. PMID:22053256

In a large Level IV case series of 2,213 hip arthroscopies with the diagnosis of femoroacetabular impingement, the intraoperative status of the ligamentum teres (LT) was recorded as normal in 11%, frayed and/or partially torn in 88%, and completely torn in 1.5% of hips. Although specific physical examination maneuvers for detecting LT tears were not available early in the study period, thus limiting a detailed assessment of such tests, the authors identified that female gender, a lower lateral center edge angle, a higher Tonnis angle, and capsular laxity were all associated with complete LT tears. This study further supports the complex coexistence of impingement and instability. PMID:27373179

Abnormal hip development causes one-quarter to one-half of all hip disease. Dysplastic hips typically share characteristic anatomic abnormalities. The dysplastic acetabulum is typically shallow, lateralized, and anteverted with insufficient coverage anteriorly, superiorly, and laterally. The dysplastic proximal femur has a small femoral head with excessive femoral neck anteversion and a short neck with an increased neck shaft angle. These characteristic changes result in intraarticular pathology leading to hip arthritis. A variety of treatment options exist based on the degree of dysplasia and the amount of concomitant hip arthritis. Treatment options include hip arthroscopy, acetabular or femoral osteotomies, hip arthrodesis, and total hip arthroplasty. PMID:25150325

The utilization of hip arthroscopy is rapidly increasing due to improved arthroscopic techniques and training, better recognition of pathology responsible for non-arthritic hip pain and an increasing desire for minimally invasive procedures. With increasing rates of arthroscopy, associated complications are also being recognized. We present a series of six patients who experienced psoas tunnel perforation during anchor insertion from the distal anterolateral portal during labral repair. All patients underwent prior hip arthroscopy and labral repair and presented with persistent symptoms at least partly attributable to magnetic resonance imaging (MRI)-documented psoas tunnel perforation. Their clinical records, operative notes and intra-operative photographs were reviewed. All patients presented with persistent pain, both with an anteriorimpingement test and resisted hip flexion. MRI imaging demonstrated medial cortical perforation with anchors visualized in the psoas tunnel, adjacent to the iliopsoas muscle. Four patients have undergone revision hip arthroscopy, whereas two have undergone periacetabular osteotomies. All patients had prominent anchors in the psoas tunnel removed at the time of surgery, with varying degrees of concomitant pathology appropriately treated during the revision procedure. Care must be utilized during medial anchor placement to avoid psoas tunnel perforation. Although this complication alone was not the sole cause for revision in each case, it may have contributed to their poor outcome and should be avoided in future cases. This can be accomplished by using a smaller anchor, inserting the anchor from the mid-anterior portal and checking the drill hole with a nitinol wire prior to anchor insertion. PMID:27011849

The utilization of hip arthroscopy is rapidly increasing due to improved arthroscopic techniques and training, better recognition of pathology responsible for non-arthritic hip pain and an increasing desire for minimally invasive procedures. With increasing rates of arthroscopy, associated complications are also being recognized. We present a series of six patients who experienced psoas tunnel perforation during anchor insertion from the distal anterolateral portal during labral repair. All patients underwent prior hip arthroscopy and labral repair and presented with persistent symptoms at least partly attributable to magnetic resonance imaging (MRI)-documented psoas tunnel perforation. Their clinical records, operative notes and intra-operative photographs were reviewed. All patients presented with persistent pain, both with an anteriorimpingement test and resisted hip flexion. MRI imaging demonstrated medial cortical perforation with anchors visualized in the psoas tunnel, adjacent to the iliopsoas muscle. Four patients have undergone revision hip arthroscopy, whereas two have undergone periacetabular osteotomies. All patients had prominent anchors in the psoas tunnel removed at the time of surgery, with varying degrees of concomitant pathology appropriately treated during the revision procedure. Care must be utilized during medial anchor placement to avoid psoas tunnel perforation. Although this complication alone was not the sole cause for revision in each case, it may have contributed to their poor outcome and should be avoided in future cases. This can be accomplished by using a smaller anchor, inserting the anchor from the mid-anterior portal and checking the drill hole with a nitinol wire prior to anchor insertion. PMID:27011849

... this view, I mean this is the traditional Smith Meet Jeu De view of the acetabulum,. I ... re using only part of what’s called the “Smith-Peterson approach.” The true Smith- Peterson, you would ...

... arch of the shoulder blade, it can cause shoulder pain called impingement syndrome. The tendons become compressed, damaged, and inflamed leading to rotator cuff tendonitis. This can occur ... use of the shoulder like baseball pitching, or from an injury.

... the bones or cartilage of your hip, including: Hip fractures – can cause sudden hip pain. These injuries can be serious and lead to major problems. Hip fractures are more common as people get older because ...

Purpose the aim of this study was to evaluate preliminary clinical and radiographic results of arthroscopic treatment of cam-type femoroacetabular impingement (FAI). Methods thirty-eight patients underwent hip arthroscopy for cam-type FAI between 2009 and 2012. Preoperative assessment was based on clinical examination, modified Harris Hip Score (mHHS) and radiographic examination with anteroposterior pelvis, frog-leg and Lequesne views. The patients’ clinical conditions at follow-up were assessed using the mHHS administered as a telephone survey. Radiographic outcome measurements evaluated pre and postoperatively were the alpha angle and femoral head-neck offset. Results the patients were clinically evaluated at a mean follow-up of 36 months. Radiographic follow-up was performed at an average of 12.7 months. Thirty of the 38 patients (79%) were satisfied with the results of the arthroscopic procedure. A total of nine patients subsequently underwent a total hip replacement. All 30 patients who declared themselves satisfied recorded an mHHS increase; in particular, the mHHS increased from a mean of 52.9 preoperatively (range: 27.5–82.5) to a mean of 85.6 postoperatively (range: 45.1–100.1). Three significant differences between the two groups of patients (satisfied and not satisfied) were recorded: mean age, alpha angle and BMI were all significantly greater in the patients who were not satisfied with the treatment. Conclusions a crucial aspect in order to obtain good clinical outcomes of arthroscopic treatment of cam-type impingement is correct selection of patients who are likely to benefit from this kind of surgery. Hip arthroscopy should be avoided in patients aged over 50 years with risk factors for early osteoarthritis (high BMI and a significantly increased alpha angle). Level of evidence Level IV, therapeutic case series. PMID:26605253

Context: Femoroacetabular impingement (FAI) is a common cause of intra-articular hip pathology and secondary osteoarthritis. It affects athletes at a young age as they push their bodies beyond the diminished physiologic limits imposed by the altered joint morphology. Understanding the cause of this condition and its assessment in athletes is important. Evidence Acquisition: The scientific literature was reviewed to reflect the current understanding of hip joint pathology among athletic individuals. Focus is given to the literature since 2003, when FAI was first reported as a cause of joint damage in the native hip. Results: There are 3 types of FAI: pincer, cam, and combined. The pathomechanics and pattern of secondary intra-articular pathology are different among the types. History and examination usually reflect findings of joint damage among athletes, and radiographs can reveal the presence of underlying FAI. Other imaging studies may variably aid in detecting the pathology. Conclusions: FAI is a common cause of hip problems in athletes. Early recognition is an important first step in order to avoid the severe secondary damage that can occur. PMID:23015955

Purpose We report short term results of open surgical treatment for symptomatic femoroacetabular impingement (FAI) in patients over the age of 30 years. Materials and Methods Between May 2011 and June 2012, thirteen FAI hips (11 patients) with hip pain persisting longer than 6 months were treated by either surgical hip dislocation (SHD) or anterior mini-open. They were followed up for longer than 2 years. The 11 patients included 7 females and 4 males with a mean age of 45 (range, 33-60) years. They were clinically evaluated for modified Harris hip score (MHHS) and University of California at Los Angeles (UCLA) activity level. Their lateral center-edge angle, acetabular index, and alpha angle were measured and compared. Results Acetabuloplasties were performed for seven cases. Femoral osteochondroplasty was performed for all thirteen cases. At minimum follow-up of two year (range, 24-29 months), all patients had substantial relief in preoperative pain with improvement in range of motion. The median MHHS was significantly (P<0.05) improved from 61 points preoperatively to 87 points at the last follow-up. The median UCLA activity level was 7 (range, 5-8) at last follow-up. Radiological indices improved. Two cases showed mild residual pain attributable to adhesion between capsule and reshaped femoral head-neck area. Conclusion Open surgical treatment of FAI was a reliable and effective treatment method in symptomatic FAIs for patients over the age of 30 years without advanced arthritic change of hip joint at short term follow-up.

Study question Is there concordance between hip pain and radiographic hip osteoarthritis? Methods In this diagnostic test study, pelvic radiographs were assessed for hip osteoarthritis in two cohorts: the Framingham Osteoarthritis Study (community of Framingham, Massachusetts) and the Osteoarthritis Initiative (a multicenter longitudinal cohort study of osteoarthritis in the United States). Using visual representation of the hip joint, participants reported whether they had hip pain on most days and the location of the pain: anterior, groin, lateral, buttocks, or low back. In the Framingham study, participants with hip pain were also examined for hip pain with internal rotation. The authors analysed the agreement between radiographic hip osteoarthritis and hip pain, and for those with hip pain suggestive of hip osteoarthritis they calculated the sensitivity, specificity, positive predictive value, and negative predictive value of radiographs as the diagnostic test. Study answer and limitations In the Framingham study (n=946), only 15.6% of hips in patients with frequent hip pain showed radiographic evidence of hip osteoarthritis, and 20.7% of hips with radiographic hip osteoarthritis were frequently painful. The sensitivity of radiographic hip osteoarthritis for hip pain localised to the groin was 36.7%, specificity 90.5%, positive predictive value 6.0%, and negative predictive value 98.9%. Results did not differ much for hip pain at other locations or for painful internal rotation. In the Osteoarthritis Initiative study (n=4366), only 9.1% of hips in patients with frequent pain showed radiographic hip osteoarthritis, and 23.8% of hips with radiographic hip osteoarthritis were frequently painful. The sensitivity of definite radiographic hip osteoarthritis for hip pain localised to the groin was 16.5%, specificity 94.0%, positive predictive value 7.1%, and negative predictive value 97.6%. Results also did not differ much for hip pain at other locations. What this

During the DFI process, high velocity flame jets impinge upon the material being heated, creating a high heat transfer rate. As a result, refractory walls and exhaust gases are cooler, which increases thermal efficiency and lowers NOx emissions. Because the jet nozzles are located a few inches from the load, furnace size can be reduced significantly.

The knee has unique anatomy regarding the relationship between the synovial and capsular layers, with interposed fat pads at certain locations. The extrasynovial impingement and inflammation syndromes about the knee are underdiagnosed and should be included in the differential diagnosis of anterior knee pain. MR imaging is the best imaging modality for evaluation of the anatomy and disorders of these extrasynovial compartments. PMID:25442030

The diagnosis and treatment of hip pain in the young adult remains a challenge. Recently, understanding of a few specific hip conditions has improved; most notably femoroacetabular impingement. The differential diagnosis of hip pain has also expanded significantly, offering new challenges and opportunities. Along with the diagnostic dilemma, optimal treatment strategies for many conditions have yet to be proven and are current areas of important inquiry. This article reviews the current research on hip pain in the young adult and presents an overview of diagnostic and management strategies. PMID:27241373

While hip arthroscopy grows in popularity, there are still many circumstances under which open hip preservation is the most appropriately indicated. This article specifically reviews open hip preservation procedures for a variety of hip conditions. Femoral acetabular impingement may be corrected using an open surgical hip dislocation. Acetabular dysplasia may be corrected using a periacetabular osteotomy. Acetabular protrusio may require surgical hip dislocation with rim trimming and a possible valgus intertrochanteric osteotomy. Legg–Calve–Perthes disease produces complex deformities that may be better served with osteotomies of the proximal femur and/or acetabulum. Chronic slipped capital femoral epiphysis may also benefit from a surgical hip dislocation and/or proximal femoral osteotomy. PMID:26649292

The most commonly reported reasons for persistent hip pain after hip arthroscopy are residual femoroacetabular impingement, dysplasia and dysplasia variants, or extra-articular impingement. There are some cases in which the underlying osseous pathomorphology has been appropriately treated, and the cause of persistent hip pain can be soft-tissue injuries such as chondrolabral tears or capsular abnormalities. Capsular defects after hip arthroscopy may suggest an alteration of the biomechanical properties of the iliofemoral ligament and lead to iatrogenically induced hip instability. There are a growing number of biomechanical and clinical studies showing the importance of capsular management during hip arthroscopy. We describe the workup, examination under anesthesia, diagnostic arthroscopy, and technique of capsular plication for iatrogenic instability of the hip. PMID:26870636

... surgeon removes damaged cartilage and bone from your hip joint and replaces them with new, man-made parts. A hip replacement can Relieve pain Help your hip joint work better Improve walking and other movements The ...

Subacromial impingement syndrome (SAIS) represents a spectrum of pathology ranging from subacromial bursitis to rotator cuff tendinopathy and full-thickness rotator cuff tears. The relationship between subacromial impingement and rotator cuff disease in the etiology of rotator cuff injury is a matter of debate. However, the etiology is multi-factorial, and it has been attributed to both extrinsic and intrinsic mechanisms. Management includes physical therapy, injections, and, for some patients, surgery. No high-quality randomized controlled trials are available so far to provide possible evidence for differences in outcome of different treatment strategies. There remains a need for high-quality clinical research on the diagnosis and treatment of SAIS. PMID:22802986

Posterior ankle impingement syndrome is a clinical disorder characterized by posterior ankle pain that occurs in forced plantar flexion. The pain may be acute as a result of trauma or chronic from repetitive stress. Pathology of the os trigonum-talar process is the most common cause of this syndrome, but it also may result from flexor hallucis longus tenosynovitis, ankle osteochondritis, subtalar joint disease, and fracture. Patients usually report chronic or recurrent posterior ankle pain caused or exacerbated by forced plantar flexion or push-off maneuvers, such as may occur during dancing, kicking, or downhill running. Diagnosis of posterior ankle impingement syndrome is based primarily on clinical history and physical examination. Radiography, scintigraphy, computed tomography, and magnetic resonance imaging depict associated bone and soft-tissue abnormalities. Symptoms typically improve with nonsurgical management, but surgery may be required in refractory cases. PMID:16224109

Jumbo acetabular cups are commonly used in revision total hip arthroplasty (THA). A straightforward reaming technique is used which is similar to primary THA. However, jumbo cups may also be associated with hip center elevation, limited screw fixation options, and anterior soft tissue impingement. A partially truncated hemispherical shell was designed with an offset center of rotation, thick superior rim, and beveled anterior and superior rims as an alternative to a conventional jumbo cup. A three dimensional computer simulation was used to assess head center position and safe screw trajectories. Results of this in vitro study indicate that a modified hemispherical implant geometry can reduce head center elevation while permitting favorable screw fixation trajectories into the pelvis in comparison to a conventional jumbo cup. PMID:26253481

Femoroacetabular impingement (FAI) is a structural abnormality of proximal femur and/or acetabulum. It has been recently described, and there are limited reports in nuclear medicine literature because bone scintigraphy is not listed in its diagnostic protocol, but it should be included on differential diagnosis when evaluating patients, with hip-related symptoms because it may be misinterpreted as degenerative changes or avascular necrosis, and its early treatment avoid progression to osteoarthritis. We describe the case of a male who suffered from hip pain. Bone planar scintigraphic appearance mimicked avascular necrosis, but single photon emission computed tomography (CT) imaging and CT examination confirmed the diagnosis of FAI. PMID:27095871

Hip arthroscopy has become an effective and reliable operative technique for treating femoroacetabular impingement (FAI). This report presents the latest arthroscopic technique, including positioning, portal placement, and treatment of the femoral and acetabular deformity and secondary lesions at the chondrolabral rim complex. After a review of the literature, the results of arthroscopic versus open treatment of FAI are compared, and an algorithm is suggested for deciding between these two types of FAI treatment. PMID:19415235

Femoroacetabular impingement (FAI) refers to a condition characterized by impingement of the femoral head-neck junction against the acetabular rim, often due to underlying osseous and/or soft tissue morphological abnormalities. It is a common cause of hip pain and limited range of motion in young and middle-aged adults. Hip preservation surgery aims to correct the morphological variants seen in FAI, thereby relieving pain and improving function, and potentially preventing early osteoarthritis. The purpose of this article is to review the mechanisms of chondral and labral injury in FAI to facilitate an understanding of patterns of chondrolabral injury seen on MRI. Preoperative MRI evaluation of FAI should include assessment of osseous morphologic abnormalities, labral tears, cartilage status, and other associated compensatory injuries of the pelvis. As advanced chondral wear is the major relative contraindication for hip preservation surgery, MRI is useful in the selection of patients likely to benefit from surgery. Teaching points • The most common anatomical osseous abnormalities predisposing to FAI include cam and pincer lesions. • Morphological abnormalities, labral lesions, and cartilage status should be assessed. • In cam impingement, chondral wear most commonly occurs anterosuperiorly.• Pre-existing advanced osteoarthritis is the strongest predictor of poor outcomes after FAI surgery. • Injury to muscles and tendons or other pelvic structures can coexist with FAI. PMID:26715128

We describe a case of femoroacetabular impingement (FAI) in a 21-year-old male U.S. Army Private. Pre-operative radiographs demonstrated a dysplastic bump at the right head-neck junction. The patient underwent arthroscopy and resection of the bump, resulting in a improved contour of the femoral head-neck junction. After standard recovery, he is now able to ambulate and flex his right hip without pain and has returned to full duty. PMID:27186247

Hip arthroscopy represents an important component in the treatment of diseases of the hip joint and is nowadays an indispensible tool in modern hip-preserving surgery. This article provides a review of the basic technical principles, typical indications and complications of hip arthroscopy. Furthermore, current developments as well as possibilities and limitations of the arthroscopic technique are reviewed. PMID:26781702

An improved liquid film impingement scrubber is provided wherein particulates suspended in a gas are removed by jetting the particle-containing gas onto a relatively small thin liquid layer impingement target surface. The impingement target is in the form of a porous material which allows a suitable contacting liquid from a pressurized chamber to exude therethrough to form a thin liquid film target surface. The gas-supported particles collected by impingement of the gas on the target are continuously removed and flushed from the system by the liquid flow through each of a number of pores in the target.

There is growing evidence that symptomatic femoroacetabular impingement leads to intra-articular damage and the development of early-onset osteoarthritis. Symptoms of femoroacetabular impingement often do not manifest until adulthood, but have been increasingly recognised in the paediatric and adolescent population. The surgical treatment of femoroacetabular impingement is aimed at restoring a more normal femoral head-neck offset in order to increase the clearance and prevent femoral abutment against the acetabular edge. Current methods include open and arthroscopic techniques. The latter has been combined with an open approach to gain access to the head-neck junction for osteochondroplasty. Proximal femoral and/or periacetabular osteotomies are used to treat femoroacetabular impingement associated with deformity secondary to childhood hip conditions, such as slipped capital femoral epiphysis and Legg-Calvé-Perthes disease. Some adolescents have severe degenerative joint disease at the time of presentation and may require arthroplasty or arthrodesis. The aim of this review is to identify the major trends and advancements in the management of femoroacetabular impingement in adolescents, including the outcome of studies of the surgical treatment modalities used. PMID:24432063

Background: Femoroacetabular impingement (FAI) is the result of a mechanical conflict in the hip joint, and its diagnosis is based on clinical and radiological parameters. To our knowledge, there are no published studies describing the radiologic characteristics of FAI in Latin American populations. Purpose: To describe the radiological features associated with FAI in an asymptomatic Chilean population. Study Design: Cross-sectional study; Level of evidence, 3. Methods: We prospectively recruited asymptomatic patients with no history or symptoms of hip pathology who underwent abdomen-pelvis computed tomography (CT) for a nonorthopaedic indication. The acetabular and femoral parameters related to FAI were measured. Results: We studied 101 subjects (202 hips) with a mean age of 36.8 ± 14.4 years. The mean center-edge angle was 39.4° ± 7.2°. The crossover sign was present in 34 cases (33.7%). The mean alpha angle was 49.7° ± 8.3°. Depending on the cut points chosen for FAI-related parameters, between 39.6% and 69.3% of an asymptomatic Chilean population were found to have morphological features related to FAI. Conclusion: Our findings suggest that the proposed pathological threshold values in the literature cannot be extrapolated to a Chilean population, and this must be taken into consideration when evaluating Latin American patients with hip pain. PMID:26535273

Objective: To familiarize the chiropractic clinician with the clinical presentation, radiographic features, and conservative versus surgical treatment options for managing femoroacetabular impingement (FAI) syndrome. Background: FAI syndrome is a relatively new clinical entity to be described in orthopedics, and has been strongly linked with pain and early osteoarthritis of the hip in young adults. Hip joint radiographs in these patients often appear normal at first—particularly if the clinician is unfamiliar with FAI. The role of conservative therapy in managing this disorder is questionable. Surgical treatment ultimately addresses any acetabular labral or articular cartilage damage, as well as the underlying osseous abnormalities associated with FAI. The most commonly used approach is open surgical hip dislocation; however, more recent surgical procedures also involve arthroscopy. Conclusion: In FAI syndrome—a condition unknown to many clinicians (including medical)—chiropractors can play an important role in its diagnosis and referral for appropriate management. PMID:20808616

Femoro-acetabular impingement is an anatomical disturbance of the hip, caused by a deformity of the acetabulum, femur or both that causes an abnormal contact between both structures during certain movements. Its prevalence is 10 to 15% and causes chronic inguinal pain. It can be confused with several other causes of inguinal pain such as hernias, facet syndromes, a renal colic, etc. Patients with this condition are usually young individuals with inguinal pain that may appear after a minor trauma. During examination, pain may be elicited by infernal rotation and abduction movements of hip, flexed in 90 degrees . Plain hip X ray is the most commonly used diagnostic method. Non-steroidal anti-inflammatory drugs and physical therapy can be used to alleviate pain, but the definitive treatment is surgical. PMID:20361159

Squeaking is a well-recognized complication for hard-on-hard bearings. The nature of squeaking is not yet completely understood however it is considered a multifactorial phenomenon. Patient, implant, and surgical factors play a role in squeaking. It is believed that mechanisms damaging the fluid film lubrication in which these bearings function optimally have a critical role. Such mechanisms include edge loading, stripe wear, impingement, third body particles and ceramic fracture. The resonance of metallic parts can produce noise in the human audible range hence the implant metallurgic composition and design may play a role. Implant positioning can facilitate impingement and edge loading enhancing the occurrence of squeaking. The recent introduction of large heads (> 36 mm) 4(th) generation ceramic-on-ceramic bearing may accentuate the conditions facilitating noise formation; however the current literature is insufficient. Clinically, squeaking may manifest in extreme hip positions or during normal gait cycle however it is rarely associated with pain. Evaluations of patients with squeaking include clinical and radiographic assessments. Computer tomography is recommended as it can better reveal ceramic breakage and implant malposition. The treatments for most squeaking patients include reassurance and activity modification. However for some, noise can be a problem, requiring further surgical intervention. In the occurrence of ceramic fracture, implant failure, extreme components malposition, instability and impingement, surgery should be advised. This review will aim to discuss the current literature regarding squeaking. PMID:26601063

Squeaking is a well-recognized complication for hard-on-hard bearings. The nature of squeaking is not yet completely understood however it is considered a multifactorial phenomenon. Patient, implant, and surgical factors play a role in squeaking. It is believed that mechanisms damaging the fluid film lubrication in which these bearings function optimally have a critical role. Such mechanisms include edge loading, stripe wear, impingement, third body particles and ceramic fracture. The resonance of metallic parts can produce noise in the human audible range hence the implant metallurgic composition and design may play a role. Implant positioning can facilitate impingement and edge loading enhancing the occurrence of squeaking. The recent introduction of large heads (> 36 mm) 4th generation ceramic-on-ceramic bearing may accentuate the conditions facilitating noise formation; however the current literature is insufficient. Clinically, squeaking may manifest in extreme hip positions or during normal gait cycle however it is rarely associated with pain. Evaluations of patients with squeaking include clinical and radiographic assessments. Computer tomography is recommended as it can better reveal ceramic breakage and implant malposition. The treatments for most squeaking patients include reassurance and activity modification. However for some, noise can be a problem, requiring further surgical intervention. In the occurrence of ceramic fracture, implant failure, extreme components malposition, instability and impingement, surgery should be advised. This review will aim to discuss the current literature regarding squeaking. PMID:26601063

Mothering in contemporary Western society needs to be understood in the context of a rapidly changing social context. Increased geographic mobility, improved access to child-related information through the media, and scientific and technological progress have contributed to significant shifts in cultural views on mothering. Several contextual impingements on mothering, including changing family structure, economic pressures, decreased social support, cultural ideals of the perfect mother, and increased awareness of interpersonal and global trauma impact mothers' internal worlds. These societal changes often reinforce mothers' fear of losing their children and an idealization of intensive mothering, and evoke challenges in reorganizing their sense of personal identity. Implications for psychoanalytic theory and practice, and specifically the need to integrate individual and contextual forces related to experiences of mothers will be explored. PMID:19295618

Computer navigation of total hip arthroplasty and computer simulation of hip motions based on collision detection were both introduced more than ten years ago. Neither of these promising technologies has achieved its full potential to improve patient outcomes. Combining these two technologies allows the individual strengths of each to more easily demonstrate hip kinematics in a clinically useful way. All normal and pathologic combined hip motions must be clearly and accurately reported to fully evaluate the kinematics involved in total hip arthroplasty, femoroacetabular impingement syndrome, and other hip disorders. The use of three-dimensional data graphs allows for a rapid and thorough evaluation of the very large data sets that are required for the purpose of making a complete report of all combined hip motions. Data can be obtained from simulations made with use of high-resolution computed tomographic scans and computer-aided implant-design files or from clinically obtained motion analysis on fresh cadavers or normal subjects. The use of these methods and graphics allows for the thorough evaluation of the geometries of current implant designs and will help improve future implant designs. The pathologic structures in hips with femoroacetabular impingement can be modeled in three dimensions, and surgical treatment plans can be developed to provide impingement-free normal hip motion without excessive osseous resection. The combination of these technologies provides hope for the improved surgical placement of total hip implants by providing the basis for a kinematic, impingement-based total hip navigation system. PMID:19182043

This is the first reported case of the completely endoscopic management of osteitis pubis with pubic symphysectomy. A 31-year-old woman suffered from recalcitrant osteitis pubis that had progressed to an end-stage auto-fused condition. Ossified pubic symphyseal fibrocartilage and adjacent heterotopic bone were endoscopically removed as part of a comprehensive surgery that also involved bilateral arthroscopic surgery for symptomatic femoroacetabular impingement. An innovative dual-portal (anterior and supra-pubic) endoscopic technique is presented along with the rationale for the preservation of the inferior (arcuate) pubic ligament and the posterior pubic ligament. Twelve months following this single-stage surgery, the patient reported high satisfaction with decreased pain, improved function, and resolution of a classic waddling gait. The association of intra-articular hip pathology with osteitis pubis is noted. We believe that this minimally invasive bone-conserving surgery may be useful in the management of recalcitrant osteitis pubis and perhaps find broader application in the outpatient endoscopic treatment of athletes afflicted with this condition. PMID:20349875

This is a report of one case of bilateral acetabular rim fracture in association with femoroacetabular impingement (FAI), which was treated with a hip arthroscopic procedure, performing a partial resection, a labral reinsertion, and a subsequential internal fixation with cannulated screws. Up to date, there are in the literature only two reports of rim fracture and “os acetabuli” in association with FAI. In the case we present, the pincer and cam resection were performed without complications; the technique used was published previously. With this technique the head of the screw lays hidden by the reattached labrum. We removed partially the fractured rim fragment and the internal fixation of the remaining portion was achieved with a screw. In the event of a complete resection of the fragment, it would have ended with a LCE angle of 18° and a high probability of hip instability. We believe that this bilateral case helps establish the efficacy and reproducibility of the technique described by Larson. PMID:25722907

... HIPS. See your doctor. Use ice and an anti-inflammatory medicine to relieve the pain. *3. Do you ... hip pain may be from ARTHRITIS. Try an anti-inflammatory medicine. If you don't feel better, see ...

... replacement is an operation in which a damaged hip joint is removed and replaced with an artificial joint. ... are many medical conditions that can damage the hip joint. (Watch the video to learn about what goes ...

Purpose The purpose of this study is to determine structural bony abnormalities predisposing for femoroacetabular impingement by comparison of patients with and without mechanical symptoms. Materials and Methods We conducted this comparative study on 151 patients (151 hips; mean age 44.8 years; range 16-73 years) with mechanical symptoms with results of multi-detector computed tomography (MDCT) arthrography (the symptomatic group). Each patient was matched with a control who underwent MDCT due to ureter stone (the asymptomatic group) in terms of age, gender, site (right or left), and time at diagnosis. Acetabular evaluations, which included cranial and central anteversion and anterior and lateral center edge angles and femoral measurements, were performed. In addition, we evaluated the prevalence and characteristics of structural bone abnormalities between the two groups. Results The prevalence for patients who had at least one structural bony abnormality in the symptomatic and asymptomatic groups was 80.1% (121/151) and 54.3% (82/151), respectively (odds ratio: 3.39, 95% confidence interval: 2.30-5.66; P<0.001). The most common osseous abnormality was the isolated Pincer type in both groups: 89 (73.6%) of 121 hips with an osseous abnormality in the symptomatic group and 57 (69.5%) of 82 hips with an osseous abnormality in the asymptomatic group. By analysis of CT arthrography in symptomatic patients, a labral tear was found in 107 hips (70.9%), and 86 (80%) of these hips had a structural bony abnormality. Conclusion A significantly greater prevalence rate of structural bony abnormality was observed for the symptomatic group than for the asymptomatic group. These findings are helpful for development of appropriate treatment plans.

Purpose The purpose of this study was to determine the prevalence of symptomatic femoroacetabular impingement (FAI) in athletic patients. Materials and Methods From July 2003 to May 2013, 388 patients (422 hips) who underwent arthroscopic surgery for FAI were evaluated demographic characteristics. The patients' age, gender, diagnosis, and type of sports were analyzed using medical records and radiography. Results Among 422 hips in 388 patients, 156 hips were involved with sports. Among the 156 hips, 86, 43, and 27 hips were categorized as cam, pincer, and mixed type, respectively. Types of sports were soccer, baseball and taekwondo which showed 44, 36 and 35 hips, respectively. Also, cases related to sports according to age were 63 hips for twenties and 12 hips for teenagers in which the two showed highest association to FAI. The kinds of sports that showed high association were 28 hips of soccer and 20 cases of martial arts such as taekwondo and judo for twenties and 9 hips of martial arts for teenagers which was the highest. Conclusion FAI usually occurs in young adults and is highly related to sports activity. Most of the FAI type related to sports activity was cam type, and soccer and martial arts such as taekwondo were the most common cause of it. PMID:27536641

This prospective study on symptomatic adult patients with femoroacetabular impingement (FAI) who underwent open surgical intervention for management was designed to identify any obvious histological differences in the damaged acetabular cartilage within different subgroups of FAI. 20 patients underwent surgical intervention following safe surgical dislocation of the hip. There were 6 cases of cam impingement, 5 cases of pincer impingement and 9 of the mixed type. Pincer impingement cases demonstrated a characteristic focal, well-circumscribed and localized area of severe damage. On the other hand, cases with cam impingement showed a diffuse area of involvement affecting a larger surface of the acetabular cartilage, with degenerative changes, superficial erosions and some discontinuities. A small biopsy specimen of the acetabular rim including bone, cartilage and labrum from the affected zone was obtained in all cases. Histological evaluation was performed under normal and polarized light microscopy. Histological findings helped corroborate the pre-operative diagnosis and also define the unique nature of impingement and specific damage according to the type of impingement. PMID:21484743

Femoroacetabular impingement (FAI) causes pain and chondrolabral damage via mechanical overload during movement of the hip. It is caused by many different types of pathoanatomy, including the cam ‘bump’, decreased head–neck offset, acetabular retroversion, global acetabular overcoverage, prominent anterior–inferior iliac spine, slipped capital femoral epiphysis, and the sequelae of childhood Perthes’ disease. Both evolutionary and developmental factors may cause FAI. Prevalence studies show that anatomic variations that cause FAI are common in the asymptomatic population. Young athletes may be predisposed to FAI because of the stress on the physis during development. Other factors, including the soft tissues, may also influence symptoms and chondrolabral damage. FAI and the resultant chondrolabral pathology are often treated arthroscopically. Although the results are favourable, morphologies can be complex, patient expectations are high and the surgery is challenging. The long-term outcomes of hip arthroscopy are still forthcoming and it is unknown if treatment of FAI will prevent arthrosis. PMID:23610655

ABSTRACT Objective: To evaluate the bleeding of the femoral head on hip osteoarthritis in patients who underwent total hip arthroplasty. Methods: One hundred and three hips affected by primary hip osteoarthritis were evaluated. After surgical dislocation, the femoral head was divided into four quadrants, and micro perforations were made in order to observe and assess the presence of bleeding, as early type (EB), late type (LB) or without bleeding (WB). Results: We observed early bleeding (EB) in the upper quadrant in 16 hips (15.5%), late bleeding in 14 hips (13.6%) and no bleeding (WB) in 73 hips (70.9%). The anterior quadrant showed EB in 24 hips (23.3%), LB in 7 hips (6.8%) and WB in 72 hips (69.9%). The lower quadrant presented EB in 40 hips (38.8%), LB 14 hips (13.6%) and WB in 49 hips (47.6%). The posterior quadrant showed EB in 39 hips (37.9%), LB 19 hips (18.4%) and WB in 45 hips (43.7%). Comparing BMI and gender, we found no association between these parameters (p> 0.05). Conclusions: The inferior and posterior quadrant had the highest bleeding levels, following the path of the medial circumflex artery. Level of Evidence III, Therapeutic Study. PMID:26981036

Plume Impingement modeling is required whenever an object immersed in a rocket exhaust plume must survive or remain undamaged within specified limits, due to thermal and pressure environments induced by the plume. At high altitudes inviscid plume models, Monte Carlo techniques along with the Plume Impingement Program can be used to predict reasonably accurate environments since there are usually no strong flowfield/body interactions or atmospheric effects. However, at low altitudes there is plume-atmospheric mixing and potential large flowfield perturbations due to plume-structure interaction. If the impinged surface is large relative to the flowfield and the flowfield is supersonic, the shock near the surface can stand off the surface several exit radii. This results in an effective total pressure that is higher than that which exists in the free plume at the surface. Additionally, in two phase plumes, there can be strong particle-gas interaction in the flowfield immediately ahead of the surface. To date there have been three levels of sophistication that have been used for low altitude plume induced environment predictions. Level 1 calculations rely on empirical characterizations of the flowfield and relatively simple impingement modeling. An example of this technique is described by Piesik. A Level 2 approach consists of characterizing the viscous plume using the SPF/2 code or RAMP2/LAMP and using the Plume Impingement Program to predict the environments. A Level 3 analysis would consist of using a Navier-Stokes code such as the FDNS code to model the flowfield and structure during a single calculation. To date, Level 1 and Level 2 type analyses have been primarily used to perform environment calculations. The recent advances in CFD modeling and computer resources allow Level 2 type analysis to be used for final design studies. Following some background on low altitude impingement, Level 1, 2, and 3 type analysis will be described.

Anteriorhip pain is common in young, active adults. Clinically, we have noted that patients with anteriorhip pain often walk in a swayback posture, and that their pain is reduced when the posture is corrected. The purpose of this study was to investigate a potential mechanism for the reduction in pain by testing the effect of posture on movement patterns and internal moments during gait in healthy subjects. Fifteen subjects were instructed to walk while maintaining three postures: 1) natural, 2) swayback, and 3) forward flexed. Kinematic and force data were collected using a motion capture system and a force plate. Walking in the swayback posture resulted in a higher peak hip extension angle, hip flexor moment and hip flexion angular impulse compared to natural posture. In contrast, walking in a forward flexed posture resulted in a decreased hip extension angle and decreased hip flexion angular impulse. Based on these results, walking in a swayback posture may result in increased forces required of the anteriorhip structures, potentially contributing to anteriorhip pain. This study provides a potential biomechanical mechanism for clinical observations that posture correction in patients with hip pain is beneficial. PMID:25262565

Recent advances in our understanding of the function of the hip capsule have clarified its importance to normal hip function and kinematics. The iliofemoral ligament is the primary stabilizing structure for controlling anterior translation and external rotation of the hip, and is violated by the arthroscopic interportal capsulotomy. Microinstability of the hip occurring after surgical trauma remains a poorly defined clinical entity. In certain at-risk populations, capsular repair should be considered as part of an arthroscopic hip procedure to achieve optimal outcomes and avoid iatrogenic instability (dislocation or microinstability). Despite a lack of conclusive evidence-based indications, we recommend capsular repair in the settings of borderline hip dysplasia (or dysplastic variants such as increased femoral anteversion), hip hypermobility, connective tissue disorders, and traumatic or atraumatic instability. With careful attention to arthroscopic capsular management, adequate exposure can be achieved and reproducibly allow for an effective capsular repair when indicated. PMID:26524549

Objective: The present study aimed to review the characteristics and influencing factors of squeaking after ceramic-on-ceramic (CoC) total hip arthroplasty (THA) and to analyze the possible mechanisms of the audible noise. Data Sources: The data analyzed in this review were based on articles from PubMed and Web of Science. Study Selection: The articles selected for review were original articles and reviews found based on the following search terms: “total hip arthroplasty”, “ceramic-on-ceramic”, “hip squeaking”, and “hip noise.” Results: The mechanism of the squeaking remains unknown. The possible explanations included stripe wear, edge loading, a third body, fracture of the ceramic liner, and resonance of the prosthesis components. Squeaking occurrence is influenced by patient, surgical, and implant factors. Conclusions: Most studies indicated that squeaking after CoC THA was the consequence of increasing wear or impingement, caused by prosthesis design, patient characteristics, or surgical factors. However, as conflicts exist among different articles, the major reasons for the squeaking remain to be identified. PMID:27453238

In newborns, US has an established role in the detection and management of developmental dysplasia of the hip. Later in childhood, when the limping child is a major diagnostic dilemma, US is extremely helpful in the identification of the varied disease processes underlying this condition, as transient synovitis, septic arthritis, Perthes disease and slipped femoral capital epiphysis. In adolescent practicing sporting activities, US is an excellent means to identify apophyseal injures about the pelvic ring, especially when avulsions are undisplaced and difficult-to-see radiographically. Later on, in the adulthood, US is an effective modality to diagnose tendon and muscle injuries about the hip and pelvis, identify effusion or synovitis within the hip joint or its adjacent bursae and guide the treatment of these findings. The aim of this article is to provide a comprehensive review of the most common pathologic conditions about the hip, in which the contribution of US is relevant for the diagnostic work-up. PMID:21571471

The present consideration of rotation effects on heat transfer in a radially exhausted, impingement-cooled turbine blade model gives attention to experimental results for Reynolds and Rossby numbers and blade/coolant temperature ratio values that are representative of small gas turbine engines. On the basis of a model that encompasses the effects of Coriolis force and buoyancy on heat transfer, bouyancy is identified as the cause of an average Nusselt number that is 20-30 percent lower than expected from previous nonrotating data. A heuristic model is proposed which predicts that the impingement jets nearest the blade roots should deflect inward, due to a centripetal force generated by their tangential velocity counter to the blade motion. Potentially serious thermal stresses must be anticipated from rotation effects in the course of blade design.

This dissertation examines the use of electric fields as one mechanism for controlling combustion as flames are partially extinguished when impinging on nearby surfaces. Electrical aspects of flames, specifically, the production of chemi-ions in hydrocarbon flames and the use of convective flows driven by these ions, have been investigated in a wide range of applications in prior work but despite this fairly comprehensive effort to study electrical aspects of combustion, relatively little research has focused on electrical phenomena near flame extinguishment, nor for flames near impingement surfaces. Electrical impinging flames have complex properties under global influences of ion-driven winds and flow field disturbances from the impingement surface. Challenges of measurements when an electric field is applied in the system have limited an understanding of changes to the flame behavior and species concentrations caused by the field. This research initially characterizes the ability of high voltage power supplies to respond on sufficiently short time scales to permit real time electrical flame actuation. The study then characterizes the influence of an electric field on the impinging flame shape, ion current and flow field of the thermal plume associated with the flame. The more significant further examinations can be separated into two parts: 1) the potential for using electric fields to control the release of carbon monoxide (CO) from surface-impinging flames, and 2) an investigation of controlling electrically the heat transfer to a plate on which the flame impinges. Carbon monoxide (CO) results from the incomplete oxidation of hydrocarbon fuels and, while CO can be desirable in some syngas processes, it is usually a dangerous emission from forest fires, gas heaters, gas stoves, or furnaces where insufficient oxygen in the core reaction does not fully oxidize the fuel to carbon dioxide and water. Determining how carbon monoxide is released and how heat transfer

Ischiofemoral impingement (IFI) is an often unrecognized cause of hip pain caused by abnormal contact between the lesser trochanter and the ischium. To date, surgical treatment for those whose pain is not relieved by activity modification and steroid injections has not been defined. This study describes our imaging protocol and reports the results of arthroscopic, lesser trochanteric resections that were performed to treat this condition. Seven patients with symptomatic, MRI-documented IFI had ultrasound injections of ropivicaine and steroid into their ischiofemoral space. The injections provided complete but only transient relief of their groin and buttock pain and thus, all seven ultimately had an arthroscopic resection of their lesser trochanter. All hips were evaluated preoperatively and at 3, 6 and 12 months postoperatively with Byrd's modified Harris hip scoring system. Average age of the seven patients was 46 years and there were five females and one male. Preoperative scores averaged 43 points. After surgery, all patients used crutches for 4-6 weeks, and had 6-week scores that averaged 58 points. The patients and their scores continued to improve and at 6 and 12 months, their scores averaged 86 and 91 points, and none had chronic hip flexor weakness or recurrence of their hip pain or snapping. Arthroscopic iliopsoas tenotomies in combination with a resection of the lesser trochanter will provide complete relief of the painful snapping, groin and buttock pain caused by ischiofemoral impingement. PMID:27583151

Ischiofemoral impingement (IFI) is an often unrecognized cause of hip pain caused by abnormal contact between the lesser trochanter and the ischium. To date, surgical treatment for those whose pain is not relieved by activity modification and steroid injections has not been defined. This study describes our imaging protocol and reports the results of arthroscopic, lesser trochanteric resections that were performed to treat this condition. Seven patients with symptomatic, MRI-documented IFI had ultrasound injections of ropivicaine and steroid into their ischiofemoral space. The injections provided complete but only transient relief of their groin and buttock pain and thus, all seven ultimately had an arthroscopic resection of their lesser trochanter. All hips were evaluated preoperatively and at 3, 6 and 12 months postoperatively with Byrd’s modified Harris hip scoring system. Average age of the seven patients was 46 years and there were five females and one male. Preoperative scores averaged 43 points. After surgery, all patients used crutches for 4–6 weeks, and had 6-week scores that averaged 58 points. The patients and their scores continued to improve and at 6 and 12 months, their scores averaged 86 and 91 points, and none had chronic hip flexor weakness or recurrence of their hip pain or snapping. Arthroscopic iliopsoas tenotomies in combination with a resection of the lesser trochanter will provide complete relief of the painful snapping, groin and buttock pain caused by ischiofemoral impingement. PMID:27583151

In this study, statistical shape modeling (SSM) was used to quantify three-dimensional (3D) variation and morphologic differences between femurs with and without cam femoroacetabular impingement (FAI). 3D surfaces were generated from CT scans of femurs from 41 controls and 30 cam FAI patients. SSM correspondence particles were optimally positioned on each surface using a gradient descent energy function. Mean shapes for control and patient groups were defined from the resulting particle configurations. Morphological differences between group mean shapes and between the control mean and individual patients were calculated. Principal component analysis was used to describe anatomical variation present in both groups. The first 6 modes (or principal components) captured statistically significant shape variations, which comprised 84% of cumulative variation among the femurs. Shape variation was greatest in femoral offset, greater trochanter height, and the head-neck junction. The mean cam femur shape protruded above the control mean by a maximum of 3.3 mm with sustained protrusions of 2.5-3.0 mm along the anterolateral head-neck junction and distally along the anterior neck, corresponding well with reported cam lesion locations and soft-tissue damage. This study provides initial evidence that SSM can describe variations in femoral morphology in both controls and cam FAI patients and may be useful for developing new measurements of pathological anatomy. SSM may also be applied to characterize cam FAI severity and provide templates to guide patient-specific surgical resection of bone.

Femoro-acetabular impingement is a common cause of hip pain in young athletes. Evaluation typically includes radiographs and magnetic resonance imaging. It is important to appreciate uncommon diagnoses and the role of complimentary imaging. This clinical vignette emphasizes the need complete imaging with CT in select case of atypical hip pain. We present a 19-year old soccer player who underwent seemingly successful arthroscopic FAI surgery but returned with pain. Computed tomography (CT) revealed osteoid osteoma of the lesser trochanter. The lesion was successfully treated with percutaneous CT guided radiofrequency ablation.

Femoro-acetabular impingement is a common cause of hip pain in young athletes. Evaluation typically includes radiographs and magnetic resonance imaging. It is important to appreciate uncommon diagnoses and the role of complimentary imaging. This clinical vignette emphasizes the need complete imaging with CT in select case of atypical hip pain. We present a 19-year old soccer player who underwent seemingly successful arthroscopic FAI surgery but returned with pain. Computed tomography (CT) revealed osteoid osteoma of the lesser trochanter. The lesion was successfully treated with percutaneous CT guided radiofrequency ablation. PMID:27583164

A girl with known proximal femoral focal deficiency presented with Perthes’ disease at 5 years of age. Her treatment involved a Salter osteotomy. This in conjunction with articular incongruence, due to deformity of the femoral head, resulted in mixed type femoroacetabular impingement when she was 10 years old. Surgical hip dislocation and femoral neck osteochondroplasty successfully relieved her symptoms of impingement. This is the first reported case of Perthes’ disease in a patient with proximal femoral focal deficiency. The case highlights the importance of thoroughly investigating pain in patients with proximal femoral focal deficiency, a condition which is normally painless. Timely diagnosis of Perthes’ disease and containment procedures can prevent collapse of the femoral head and the resultant sequelae. Acetabular over-coverage should be avoided in pelvic osteotomy to prevent the development of femoroacetabular impingement. PMID:23148394

Significantly reduced distance between the ischium and the femur can result in symptomatic hip pain as a result of impingement. We present the case of a 16-year-old boy who presented with groin pain which had been affecting him for a year and a half following an innocuous football injury. Plain radiograph revealed a chronic apophyseal avulsion fracture of the ischium with excessive callus formation. CT scan and MRI revealed that the bony protuberance was responsible for symptomatic ischiofemoral impingement. In this case, he was successfully treated with non-operative management involving slow re-introduction to exercise. An unusual example of acquired ischiofemoral impingement, unrelated to surgery or significant trauma, this case highlights the need to consider such a diagnosis in otherwise unexplained groin pain. PMID:24966262

... hip replacement surgery, the damaged portions of the hip joint are removed. The ball (femoral head) is removed ... hip or leg Swelling at or near the hip joint A limp or change in walking ability Noise ( ...

Changes in muscle activities are commonly associated with shoulder impingement and theoretically caused by changes in motor program strategies. The purpose of this study was to assess for differences in latencies and deactivation times of scapular muscles between subjects with and without shoulder impingement. Twenty-five healthy subjects and 24 subjects with impingement symptoms were recruited. Glenohumeral kinematic data and myoelectric activities using surface electrodes from upper trapezius (UT), lower trapezius (LT), serratus anterior (SA) and anterior fibers of deltoid were collected as subjects raised and lowered their arm in response to a visual cue. Data were collected during unloaded, loaded and after repetitive arm raising motion conditions. The variables were analyzed using 2 or 3 way mixed model ANOVAs. Subjects with impingement demonstrated significantly earlier contraction of UT while raising in the unloaded condition and an earlier deactivation of SA across all conditions during lowering of the arm. All subjects exhibited an earlier activation and delayed deactivation of LT and SA in conditions with a weight held in hand. The subjects with impingement showed some significant differences to indicate possible differences in motor control strategies. Rehabilitation measures should consider appropriate training measures to improve movement patterns and muscle control. PMID:23137918

Neurological and vascular complications following hip arthroplasty are uncommon, and their impact ranges from transient and trivial to permanent and devastating. The proximity of neural and vascular structures makes any operation on the hip potentially hazardous. Direct or indirect injuries of these structures may occur during operative exposure and subsequent procedures. Thus, complete awareness of the anatomy of the pelvis and proximal femur is required. Peripheral nerve injuries can involve either distant sites or nerves in the immediate vicinity of the hip joint. Sciatic nerve injury is the most common nerve injury following total hip arthroplasty. Femoral nerve injury is much less common and is associated with an anterior approach. Its diagnosis is often delayed, but the prognosis is generally better than with sciatic nerve injury. The superior gluteal nerve is at risk during the direct lateral approach. Obturator nerve injury is the least common type of injury and has the least functional consequences. Vascular injuries are less common but more immediately life threatening. The mechanisms of vascular injury include occlusion associated with preexisting peripheral vascular disease and vascular injury during removal of cement during screw fixation of acetabular components, cages, or structural grafts. It is critical to avoid the anterior quadrants for acetabular screw fixation. All acetabular and femoral defects should be bone-grafted to avoid inadvertent cement migration. Following these guidelines, surgeons should be able to offer the most appropriate treatment and counseling to the patients.

The "optimal" positioning of the cup in total hip arthroplasty can improve hip function and reduce wear, impingement and dislocation. The cup position is described as the spatial relation between the hip rotation centre and the pelvis and, as the cup orientation around the rotation centre. The first parameter affects hip balance and, if not managed properly, might result in poor function and leg length discrepancy. The second parameter is often "silent", unless impingement or dislocation occurs. However, inappropriate cup orientation can accelerate wear and cause early failure. As such, it is mandatory to get both right, taking into account multiple parameters: the stem position, the approach, the bearing surface, the cup coverage and the pelvic orientation during loading. In most cases a "standard" cup position is adequate. However, specific anatomic features might require an individualized approach. This paper aims at reviewing the parameters that impact on the optimal cup position. This should allow for more judicious choices in those particular cases. PMID:26280607

Two complications after total hip arthroplasty (THA) are hip instability and limb length discrepancy; instability is a common indication for revision THA. The goal of a successful THA is to maximize impingement-free range of motion, recreate appropriate offset, and equalize limb length discrepancies to produce a pain-free and dynamically stable THA. In this article, the patient risk factors for dislocation and limb length discrepancy, key elements of the preoperative template, the anatomic landmarks for accurate component placement, the leg positions for soft tissue stability testing, and the management of postoperative instability are reviewed. PMID:26772941

Objective Hip pain and injury as a result of activity can lead to the development of early hip osteoarthritis (OA) in susceptible individuals. Our understanding of the factors that increase susceptibility continues to evolve. The ability to clearly identify individuals (and cohorts) with activity-related hip pain who are at risk of early hip OA is currently lacking. The purpose of this study was to gain expert consensus on which key clinical measures might help predict the risk of early hip OA in individuals presenting with activity-related hip pain. The agreed measures would constitute a standardised approach to initial clinical assessment to help identify these individuals. Methods This Dephi study used online surveys to gain concordance of expert opinion in a structured process of ‘rounds’. In this study, we asked ‘What outcome measures are useful in predicting hip OA in activity-related hip pain?’ The Delphi panel consisted of experts from sport and exercise medicine, orthopaedics, rheumatology, physiotherapy and OA research. Results The study identified key clinical measures in the history, examination and investigations (plain anteroposterior radiograph and femoroacetabular impingement views) that the panel agreed would be useful in predicting future risk of hip OA when assessing activity-related hip pain. The panel also agreed that certain investigations and tests (eg, MR angiography) did not currently have a role in routine assessment. There was a lack of consensus regarding the role of MRI, patient-reported outcome measures (PROMs) and certain biomechanical and functional assessments. Conclusions We provide a standardised approach to the clinical assessment of patients with activity-related hip pain. Assessment measures rejected by the Delphi panel were newer, more expensive investigations that currently lack evidence. Assessment measures that did not reach consensus include MRI and PROMs. Their role remains ambiguous and would benefit from further

Surgical hip dislocation is the gold standard for treatment of femoroacetabular impingement (FAI). It utilizes an intermuscular and internervous approach to the hip. Concerns have been expressed that this approach causes soft tissue trauma resulting in post-operative muscle weakness of patients undergoing this procedure. We therefore asked whether surgical hip dislocation leads to (i) atrophy (decreased muscle diameter or cross-sectional area [CSA]) and (ii) degeneration (fatty infiltration) of 18 evaluated periarticular hip muscles. We retrospectively evaluated 32 patients (34 hips) following surgical hip dislocation for the treatment of FAI using pre and post-operative magnetic resonance (MR) arthrography of the hip. We evaluated muscle diameter, CSA and degree of fatty infiltration according to Goutallier for 18 periarticular hip muscles on axial and sagittal views. The mean interval between pre and post-operative MR was 1.9 ± 1.5 years (range, 0.4–6.1 years). Pre and post-operative muscle diameter and CSA of all 18 evaluated hip muscles did not differ. There was no post-operative change in the Goutallier classification for any of the evaluated 18 muscles. No muscle had post-operative degeneration higher than Grade 1 according to Goutallier. No atrophy or degeneration of periarticular hip muscles could be found following surgical hip dislocation for treatment of FAI. Any raised concerns about the invasiveness and potential muscle trauma for this type of surgery are unfounded. Level III, retrospective comparative study. See guidelines for authors for a complete description of levels of evidence. PMID:27011807

'Hip' pain is usually located in the groin, upper thigh or buttock and is a common complaint. Slipped capital femoral epiphysis, avascular femoral head necrosis and apophyseal avulsion are the most common diagnoses in childhood and adolescents. Strains and fractures are common in sport-active adults. Osteoarthritis occurs in middle-aged and older adults. Trauma may result in femoral head fracture or typical muscle and tendon sprains and bursitis. Septic or inflammatory arthritis can occur at every age. Septic arthritis, fractures and acute epiphyseal slipping are real emergency cases. Congenital dysplasia of the hip joint may lead to labral tears and early osteoarthritis. The most important hip problems in children, adolescents, adult and older people are discussed; these problems originate from intra-articular disorders and the surrounding extra-articular soft tissues. Medical history, clinical examination and additional tests, including imaging, will be demonstrated. Principles of treatment are given for specific disorders. PMID:12659822

Objective: Describe the results from arthroscopic surgical treatment on a group of patients who developed symptoms after repetitive physical activity of moving their hips in a position of hyperflexion, as in leg presses and squats. Methods: The study group comprised 47 individuals (48 hips) who developed the onset of painful symptoms associated with hip hyperflexion exercises (leg presses or squats) and underwent arthroscopic treatment. The patients were evaluated radiographically and clinically according to the “Harris Hip Score", as modified by Byrd (MHHS), pre and postoperatively, and were asked about their return to sports activities and the surgical findings. Results: The mean preoperative and postoperative MHHS, respectively, were 60 points (SD 11.0, range 38.5 to 92.4) and 95.9 points (SD 7.7, range 63.8 to 100), with an increase of 35.9 points (P < 0.001). Regarding physical activity, 30 individuals (71.5%) resumed sports activities after surgery, and 25 of them (83.4%) at the previous level. Six patients (12.8%) did not resume activities because of persistent pain. During arthroscopy, 48 hips (100%) presented lesions of the acetabular labrum, and 41 hips (85.4%) had acetabular chondral lesions. Conclusion: The patients with painful symptoms after hip hyperflexion exercises associated with femoroacetabular impingement presented improvements after arthroscopic treatment. PMID:27047856

The differential diagnosis of hip pain is broad and includes intra-articular pathology, extra-articular pathology, and mimickers, including the joints of the pelvic ring. With the current advancements in hip arthroscopy, more patients are being evaluated for hip pain. In recent years, our understanding of the functional anatomy around the hip has improved. In addition, because of advancements in magnetic resonance imaging, the diagnosis of soft tissue causes of hip pain has improved. All of these advances have broadened the differential diagnosis of pain around the hip joint and improved the treatment of these problems. In this review, we discuss the causes of intra-articular hip pain that can be addressed arthroscopically: labral tears, loose bodies, femoroacetabular impingement, capsular laxity, tears of the ligamentum teres, and chondral damage. Extra-articular diagnoses that can be managed arthroscopically are also discussed, including: iliopsoas tendonitis, "internal" snapping hip, "external" snapping hip, iliotibial band and greater trochanteric bursitis, and gluteal tendon injury. Finally, we discuss extra-articular causes of hip pain that are often managed nonoperatively or in an open fashion: femoral neck stress fracture, adductor strain, piriformis syndrome, sacroiliac joint pain, athletic pubalgia, "sports hernia," "Gilmore's groin," and osteitis pubis. PMID:19038713

Hip arthroscopy has gained popularity in recent years for diagnostic and therapeutic hip preservation management. This article details the establishment of arthroscopic portals of the hip, specifically the anterolateral and modified anterior portals without fluoroscopic guidance. The anterolateral portal is established anatomically, and the modified anterior portal is then established under arthroscopic guidance. A through understanding of the hip anatomy allows for these portals to be made both safely and reliably for hip arthroscopies in the modified supine positioned patient. The reduced use of fluoroscopy with this technique lowers the risk of ionizing radiation exposure to the patient and surgeon. PMID:27489756

Ischiofemoral impingement syndrome (IFI) is an underrecognized form of atypical, extra-articular hipimpingement defined by hip pain related to narrowing of the space between the ischial tuberosity and the femur. The etiology of IFI is multifactorial and potential sources of ischiofemoral engagement include anatomic variants of the proximal femur or pelvis, functional disorders as hip instability, pelvic/spinal instability, or abductor/adductor imbalance, ischial tuberosity enthesopathies, trauma/overuse or extreme hip motion, iatrogenic conditions, tumors and other pathologies. Magnetic resonance imaging (MRI) is the diagnostic procedure of choice for assessing IFI and may substantially influence patient management. The injection test of the ischiofemoral space (IFS) has both a diagnostic and therapeutic function. Endoscopic decompression of the IFS appears useful in improving function and diminishing hip pain in patients with IFI but conservative treatment is always the first step in the treatment algorithm. Because of the ever-increasing use of advanced MRI techniques, the frequent response to conservative treatment, and the excellent outcomes of new endoscopic treatment, radiologists must be aware of factors that predispose or cause IFI. In addition, focused treatment in these conditions is often more important than in secondary impingement. In this article, we briefly describe the anatomy of the IFS, review the clinical examination and symptoms, assess the diagnostic imaging criteria and pathophysiological mechanisms, and develop an understandable classification of IFI, with particular focus on its etiology, predisposing factors, and associated musculoskeletal abnormalities. We also assess the role of the radiologist in the diagnosis, treatment, and preoperative evaluation of both primary and secondary IFI. PMID:26940209

Droplet trajectories about a sphere in ideal fluid flow were calculated. From the calculated droplet trajectories the droplet impingement characteristics of the sphere were determined. Impingement data and equations for determining the collection efficiency, the area, and the distribution of impingement are presented in terms of dimensionless parameters. The range of flight and atmospheric conditions covered in the calculations was extended considerably beyond the range covered by previously reported calculations for the sphere.

An investigation of externally blown flap impingement noise was conducted using a full-scale turbofan engine and aircraft wing. The noise produced with a daisy nozzle installed on the engine exhaust system was greater than that produced by a conical nozzle at the same thrust. The daisy nozzle caused the jet velocity to decay about 35 percent at the flap. The presence of the wing next to the conical nozzle increased the noise, as did increasing the flap deflection. Compared with the conical nozzle, the daisy nozzle produced slightly less noise at a flap deflection of 60 deg but produced more noise at the lower flap deflections tested.

Cam and pincer are two common morphologies responsible for femoroacetabular impingement (FAI). Previous literature has reported that cam deformity is predominantly a male morphology, while being significantly less common in females. Cam morphology is commonly assessed with the alpha angle, measured on radiographs. The purpose of this study is to determine the prevalence of cam morphology utilizing the alpha angle in female subjects diagnosed with symptomatic FAI. All females presenting to the senior author’s clinic diagnosed with symptomatic FAI between December 2006 and January 2013 were retrospectively reviewed. Alpha (α) angles were measured on anteroposterior and lateral (Dunn 90°, cross-table lateral, and/or frog-leg lateral) plain radiographs by two blinded physicians, and the largest measured angle was used. Using Gosvig et al.’s classification, alpha angle was characterized as (pathologic > 57°), borderline (51–56°), subtle (46–50°), very subtle (43–45°), or normal (≤42°). Three hundred and ninety-one patients (438 hips) were analyzed (age 36.2 ± 12.3 years). Among the hips included, 35.6% were normal, 14.6% pathologic, 15.1% borderline, 14.6% subtle, and 20.1% very subtle. There was no correlation between alpha angle and patient age (R = 0.17) or body mass index (R = 0.05). The intraclass correlation coefficient for α-angle measurements was 0.84. Sixty-four percent of females in this cohort had an alpha angle >42°. Subtle cam deformity plays a significant role in the pathoanatomy of female patients with symptomatic FAI. As the majority of revision hip arthroscopies are performed due to incomplete cam correction, hip arthroscopists need to be cognizant of and potentially surgically address these subtle lesions. PMID:26649291

Background: Two of the most common causes of groin pain in athletes are femoroacetabular impingement (FAI) and athletic pubalgia. An association between the 2 is apparent, but the prevalence of radiographic signs of FAI in patients undergoing athletic pubalgia surgery remains unknown. The purpose of this study was to determine the prevalence of radiologic signs of FAI in patients with athletic pubalgia. Hypothesis: We hypothesized that patients with athletic pubalgia would have a high prevalence of underlying FAI. Study Design: Case series. Level of Evidence: Level 4. Methods: A retrospective review of all patients evaluated at our institution with athletic pubalgia who underwent surgical treatment (ie, for sports hernia) from 1999 to 2011 was performed. The radiographs of patients with athletic pubalgia were reviewed for radiographic signs of FAI. Alpha angles were measured using frog-leg lateral radiographs. Pincer lesions were identified by measuring the lateral center-edge angle and identifying the presence of a “crossover” sign on anteroposterior radiographs. Phone follow-up was performed 2 years or more after the initial sports hernia surgery to evaluate recurrent symptoms. Results: Forty-three patients underwent 56 athletic pubalgia surgeries. Radiographic evidence of FAI was identified in at least 1 hip in 37 of 43 patients (86%). Cam lesions were identified in 83.7% of the population; the alpha angle averaged 66.7° ± 17.9° for all hips. Pincer lesions were present in 28% of the hips. Eight patients had recurrent groin pain, 3 patients had revision athletic pubalgia surgery, and 1 had hip arthroscopy. Conclusion: The study demonstrates a high prevalence of radiographic FAI in patients with athletic pubalgia. Clinical Relevance: Underlying FAI may be a cause of continued groin pain after athletic pubalgia surgery. Patients with athletic pubalgia should be evaluated closely for FAI. PMID:24587869

Experimental investigation to study the heat transfer between a vertical round alumina-water nanofluid jet and a horizontal circular round surface is carried out. Different jet flow rates, jet nozzle diameters, various circular disk diameters and three nanoparticles concentrations (0, 6.6 and 10%, respectively) are used. The experimental results indicate that using nanofluid as a heat transfer carrier can enhance the heat transfer process. For the same Reynolds number, the experimental data show an increase in the Nusselt numbers as the nanoparticle concentration increases. Size of heating disk diameters shows reverse effect on heat transfer. It is also found that presenting the data in terms of Reynolds number at impingement jet diameter can take into account on both effects of jet heights and nozzle diameter. Presenting the data in terms of Peclet numbers, at fixed impingement nozzle diameter, makes the data less sensitive to the percentage change of the nanoparticle concentrations. Finally, general heat transfer correlation is obtained verses Peclet numbers using nanoparticle concentrations and the nozzle diameter ratio as parameters. PMID:22340669

Experimental investigation to study the heat transfer between a vertical round alumina-water nanofluid jet and a horizontal circular round surface is carried out. Different jet flow rates, jet nozzle diameters, various circular disk diameters and three nanoparticles concentrations (0, 6.6 and 10%, respectively) are used. The experimental results indicate that using nanofluid as a heat transfer carrier can enhance the heat transfer process. For the same Reynolds number, the experimental data show an increase in the Nusselt numbers as the nanoparticle concentration increases. Size of heating disk diameters shows reverse effect on heat transfer. It is also found that presenting the data in terms of Reynolds number at impingement jet diameter can take into account on both effects of jet heights and nozzle diameter. Presenting the data in terms of Peclet numbers, at fixed impingement nozzle diameter, makes the data less sensitive to the percentage change of the nanoparticle concentrations. Finally, general heat transfer correlation is obtained verses Peclet numbers using nanoparticle concentrations and the nozzle diameter ratio as parameters. PMID:22340669

This technical note describes a new method that allows access to the central compartment of the hip under arthroscopic control via the peripheral compartment with less risk of labral perforation and/or cartilage scuffing. After placement of the anterolateral portal in the peripheral compartment without traction, the anterior head area with the anterior acetabular labrum and the anterior surface of the femoral head are inspected. Under arthroscopic control, a guidewire is introduced through the anterior portal in between the anterior labrum and anterior femoral head cartilage and into the central compartment. The arthroscope is then removed from the anterolateral portal, the hip distracted, and the arthroscope introduced via cannulated instruments over the guidewire into the central compartment. Further portal placement can be controlled arthroscopically. PMID:16376244

An experiment was designed to create a simplified simulation of the flow through a hole in the surface of a hypersonic aerospace vehicle and the subsequent impingement of the flow on internal structures. In addition to planar laser-induced fluorescence (PLIF) flow visualization, pressure measurements were recorded on the surface of an impingement target. The PLIF images themselves provide quantitative spatial information about structure of the impinging jets. The images also help in the interpretation of impingement surface pressure profiles by highlighting the flow structures corresponding to distinctive features of these pressure profiles. The shape of the pressure distribution along the impingement surface was found to be double-peaked in cases with a sufficiently high jet-exit-to-ambient pressure ratio so as to have a Mach disk, as well as in cases where a flow feature called a recirculation bubble formed at the impingement surface. The formation of a recirculation bubble was in turn found to depend very sensitively upon the jet-exit-to-ambient pressure ratio. The pressure measured at the surface was typically less than half the nozzle plenum pressure at low jet pressure ratios and decreased with increasing jet pressure ratios. Angled impingement cases showed that impingement at a 60deg angle resulted in up to a factor of three increase in maximum pressure at the plate compared to normal incidence.

In present study, the bistability and hysteresis of annular impinging jets is investigated. Annular impinging jets are simulated using open source CFD code - OpenFOAM. Both flow field patterns of interest are obtained and hysteresis is found by means of dynamic mesh simulation. Effect of nozzle exit velocity on resulting hysteresis loop is also illustrated.

Femoroacetabular impingement (FAI) is characterized by an abnormality in the shape of the femoral head-neck or acetabulum that results in impingement between these two structures. Arthroscopic treatment has become the preferred method of management of FAI owing to its minimally invasive approach. Surgical correction involves resection of impinging osseous structures as well as concurrent management of the associated chondral and labral pathology. Research from the past 5 years has shown that repair of the labrum results in a better anatomic correction and improved outcomes compared with labral debridement. Research is underway to improve cartilage assessment by using innovative imaging techniques and biochemical tests to inform predictions of prognosis. Several ongoing randomized controlled trials, including the Femoroacetabular Impingement Trial (FAIT) and the Femoroacetabular Impingement Randomized Controlled Trial (FIRST), will provide critical information regarding the diagnosis, management and prognosis of patients undergoing arthroscopic management of FAI. PMID:26963727

Tests of the noise produced by the impingement of the jet exhaust on the wing and flap for an externally blown flap system were conducted with a CF700 turbofan engine and an F-111B wing panel. The noise produced with a daisy nozzle installed on the engine was greater than that produced by a conical nozzle at the same thrust. The presence of the wing next to the test nozzles increased the noise, as did increasing the flap deflection angle. Compared with the conical nozzle, the daisy nozzle produced slightly less noise at a flap deflection of 60 deg but produced more noise at the lower flap deflections tested. Tests showed that the single-slotted flap deflected 60 deg, produced less noise than the double-slotted flaps. Also, maintaining the maximum distance between the exit nozzle and flap system resulted in a minor reduction in noise.

Purpose : Hip arthroscopy is a well established therapeutic intervention for an increasing number of painful hip conditions. Developmental dysplasia of the hip (DDH) is commonly associated with intra-articular hip pathology. However, some surgeons perceive patients with hip dysplasia as poor candidates for hip arthroscopy. Our aim was to describe early outcomes of arthroscopic treatment for patients with DDH, who also had femoroacetabular impingement (FAI) treated when necessary, and to compare these outcomes against a control group of patients without DDH. Methods : Prospective case-control study of 68 consecutive hip arthroscopy patients assessed with a modified Harris Hip Score (mHHS) preoperatively and at six weeks, six months, and one year after surgery. Presence of DDH was determined using a standard anteroposterior (AP) pelvic radiograph to measure the centre-edge angle (CEA) of Wiberg, with a CEA < 20º used as threshold for diagnosis of DDH. Results : 12 patients (eight female and four male) with acetabular dysplasia and mean CEA of 15.4º (9º to 19º). The control, nondysplastic group comprised 54 patients (23 females and 31 males) with a mean CEA of 33.1º (22º to 45º). All patients in the dysplastic group had a labral tear and 11 (91.7%) had associated femoral cam impingement lesion addressed at arthroscopy. Our study demonstrates a significant (p=0.02) improvement in outcome in the dysplastic group at one year using the mHHS. Conclusion : Hip arthroscopy in the presence of DDH is effective in relieving pain for at least one year after surgery although does not address underlying acetabular abnormality. PMID:26069512

Symptomatic femoroacetabular impingement (FAI) is now a known precursor of early osteoarthritis (OA) of the hip. In terms of clinical intervention, the decision between joint preservation and joint replacement hinges on the severity of articular cartilage degeneration. The exact threshold during the course of disease progression when the cartilage damage is irreparable remains elusive. The intention behind radiographic imaging is to accurately identify the morphology of osseous structural abnormalities and to accurately characterize the chondrolabral damage as much as possible. However, both plain radiographs and computed tomography (CT) are insensitive for articular cartilage anatomy and pathology. Advanced magnetic resonance imaging (MRI) techniques include magnetic resonance arthrography and biochemically sensitive techniques of delayed gadolinium-enhanced MRI of cartilage (dGEMRIC), T1rho (T1ρ), T2/T2* mapping, and several others. The diagnostic performance of these techniques to evaluate cartilage degeneration could improve the ability to predict an individual patient-specific outcome with non-surgical and surgical care. This review discusses the facts and current applications of biochemical MRI for hip joint cartilage assessment covering the roles of dGEMRIC, T2/T2*, and T1ρ mapping. The basics of each technique and their specific role in FAI assessment are outlined. Current limitations and potential pitfalls as well as future directions of biochemical imaging are also outlined. PMID:26258129

Symptomatic femoroacetabular impingement (FAI) is now a known precursor of early osteoarthritis (OA) of the hip. In terms of clinical intervention, the decision between joint preservation and joint replacement hinges on the severity of articular cartilage degeneration. The exact threshold during the course of disease progression when the cartilage damage is irreparable remains elusive. The intention behind radiographic imaging is to accurately identify the morphology of osseous structural abnormalities and to accurately characterize the chondrolabral damage as much as possible. However, both plain radiographs and computed tomography (CT) are insensitive for articular cartilage anatomy and pathology. Advanced magnetic resonance imaging (MRI) techniques include magnetic resonance arthrography and biochemically sensitive techniques of delayed gadolinium-enhanced MRI of cartilage (dGEMRIC), T1rho (T1ρ), T2/T2* mapping, and several others. The diagnostic performance of these techniques to evaluate cartilage degeneration could improve the ability to predict an individual patient-specific outcome with non-surgical and surgical care. This review discusses the facts and current applications of biochemical MRI for hip joint cartilage assessment covering the roles of dGEMRIC, T2/T2*, and T1ρ mapping. The basics of each technique and their specific role in FAI assessment are outlined. Current limitations and potential pitfalls as well as future directions of biochemical imaging are also outlined. PMID:26258129

Impingement is the most common cause of pain and limitation of movement in the shoulder, with painful arc syndrome its major clinical sign. It usually becomes manifest at between 70 degrees-120 degrees of abduction, but in severe cases, this may be reduced to only 50 degrees-70 degrees. We studied 22 patients who had developed shoulder impingement following direct injuries and who had been treated by anterior acromioplasty and decompression, with an average follow-up of 32 months. 5 had sustained fractures of the greater tuberosity of the humerus at the time of injury, 14 had tears of the rotator cuff of various sizes (1 in both shoulders) and 3 had developed fibrotic scars of the subacromial bursa. Excellent or good results were achieved in 86.6%. Healing time was shorter, and there was return of full range of shoulder movement in those with subacromial scars, undisplaced fractures of the greater tuberosity, or those with a small tear of the rotator cuff. Recovery took longer in those with larger tears of the rotator cuff and in those with displaced fractures of the greater tuberosity. Recovery time was proportional to the size of the rotator cuff tear. It is concluded that direct trauma to the shoulder bears a direct relationship to the development of impingement syndrome, and that at surgery a concomitant tear in the rotator cuff is seen more than 2/3. Because of the high rate of success in surgical treatment of this syndrome, operation is indicated when a few months of physical therapy and analgesics fail to provide relief. In the presence of fractures, decompression surgery should be postponed until the fracture has united. PMID:8675117

A 53-year-old man presented with pain in the right hip. Radiological examination showed idiopathic osteonecrosis of the femoral head (ONFH) combined with a cam lesion. Findings on physical examination were consistent for femoroacetabular impingement. At surgery, we performed isolated arthroscopic correction for the cam lesion but did not use other treatment options such as hip arthroplasty or osteotomies for the ONFH. At the latest follow-up evaluation 3 years after surgery, findings indicted a satisfactory outcome, with a Harris hip score of 93.2 (compared with 76.4 before surgery), no joint-space narrowing, and no collapse of the femoral head. It is important to accurately diagnose the status of idiopathic ONFH and to consider another possible pathogenesis when a patient with idiopathic ONFH has hip pain even without femoral-head collapse. PMID:26773875

A normally functioning hip joint is imperative for athletes who use their lower extremities with running, jumping, or kicking activities. Sports-related injuries of the hip and groin are far less frequent than injuries to the more distal aspect of the extremity, accounting for less than 10% of lower extremity injuries. Despite the lower incidence, hip and groin injuries can lead to significant clinical and diagnostic challenges related to the complex anatomy and biomechanical considerations of this region. Loads up to 8 times normal body weight have been documented in the joint in common daily activities, such as jogging, with significantly greater force expected during competitive athletics. Additionally, treatment for hip and groin injuries can obviate the participation of medical and surgical specialties, with a multidisciplinary approach frequently required. Delay in diagnosis and triage of these injuries may cause loss of time from competition and, potentially, early onset of degenerative changes. Magnetic resonance imaging (MRI) of the hip has proven to be the gold standard for the diagnosis of sports-related hip and groin injuries in the setting of negative radiographs. With its exquisite soft tissue contrast, multiplanar capabilities, and lack of ionizing radiation, MRI is unmatched in the noninvasive diagnosis of intra-articular and extra-articular pathology, as well as intraosseous processes. This review focuses on MRI of common athletic injuries of the hip and groin, including acetabular labral tears, femoral acetabular impingement syndrome, muscle injuries around the hip and groin (including athletic pubalgia), and athletic osseous injuries. PMID:23015946

A normally functioning hip joint is imperative for athletes who use their lower extremities with running, jumping, or kicking activities. Sports-related injuries of the hip and groin are far less frequent than injuries to the more distal aspect of the extremity, accounting for less than 10% of lower extremity injuries. Despite the lower incidence, hip and groin injuries can lead to significant clinical and diagnostic challenges related to the complex anatomy and biomechanical considerations of this region. Loads up to 8 times normal body weight have been documented in the joint in common daily activities, such as jogging, with significantly greater force expected during competitive athletics. Additionally, treatment for hip and groin injuries can obviate the participation of medical and surgical specialties, with a multidisciplinary approach frequently required. Delay in diagnosis and triage of these injuries may cause loss of time from competition and, potentially, early onset of degenerative changes. Magnetic resonance imaging (MRI) of the hip has proven to be the gold standard for the diagnosis of sports-related hip and groin injuries in the setting of negative radiographs. With its exquisite soft tissue contrast, multiplanar capabilities, and lack of ionizing radiation, MRI is unmatched in the noninvasive diagnosis of intra-articular and extra-articular pathology, as well as intraosseous processes. This review focuses on MRI of common athletic injuries of the hip and groin, including acetabular labral tears, femoral acetabular impingement syndrome, muscle injuries around the hip and groin (including athletic pubalgia), and athletic osseous injuries. PMID:23015946

The purpose of this study was to evaluate the validity and reliability of a radiographic diagnosis of femoroacetabular impingement (FAI) by a non-radiologist. Symptomatic FAI is prevalent and thought to be a cause of hip osteoarthritis. However, the diagnosis is often delayed by 1-2 years, in large part because radiographic findings are often subtle and clinicians have been unaware of their significance. The purpose of this study was to evaluate the validity of a radiographic diagnosis of FAI by a non-radiologist. A population-based sample of 701 subjects was recruited in Vancouver, Canada. For the current study, 50 subjects were selected-40 randomly from the population sample and 10 from an orthopedic practice with confirmed FAI. An anterior-posterior pelvis and bilateral Dunn radiographs were acquired and read by a fellowship-trained musculoskeletal radiologist and a third-year medical student who received basic training in radiographic signs of FAI. Three radiographic signs were evaluated: the lateral center edge angle, alpha angle and crossover sign. Validity was assessed using sensitivity and specificity, Bland-Altman limits of agreement and kappa. The sample contained 65% women (n = 31), was 62% Caucasian and 38% Chinese and had a mean age of 38.3 years. For correctly diagnosing FAI, the non-radiologist reader had a sensitivity of 0.83 and specificity of 0.87. Intra-rater κ value was 0.72, and prevalence-adjusted bias-adjusted κ was 0.76. This study provides evidence that a non-radiologist can accurately and reliably identify FAI on plain films. PMID:26433895

Objective To determine the strength of common radiographic and radial CT views for measuring true femoral head asphericity. Patients and Methods In 15 patients with cam femoroacetabular impingement (FAI) and 15 controls, alpha angles were measured by two observers using radial CT (0°, 30°, 60°, 90°) and digitally reconstructed radiographs (DRRs) for the: anterior-posterior (AP), standing frog-leg lateral, 45° Dunn with neutral rotation, 45° Dunn with 40°external rotation, and cross-table lateral views. A DRR validation study was performed. Alpha angles were compared between groups. Maximum deviation from a sphere of each subject was obtained from a previous study. Alpha angles from each view were correlated with maximum deviation. Results There were no significant differences between alpha angles measured on radiographs and the corresponding DRRs (p = 0.72). Alpha angles were significantly greater in patients for all views (p ≤0.002). Alpha angles from the 45° Dunn with 40° external rotation, cross-table lateral, and 60° radial views had the strongest correlations with maximum deviation (r = 0.831; r = 0.823; r=0.808, respectively). The AP view had the weakest correlation (r = 0.358). Conclusion DRRs were a validated means to simulate hip radiographs. The 45° Dunn with 40° external rotation, cross-table lateral, and 60° radial views best visualized femoral asphericity. Although commonly used, the AP view did not visualize cam deformities well. Overall, the magnitude of the alpha angle may not be indicative of the size of the deformity. Thus, 3D reconstructions and measurements of asphericity could improve the diagnosis of cam FAI. PMID:24613175

Femoroacetabular impingement may be particularly disabling to the high-demand athlete, especially those with significant cutting and pivoting requirements. If nonoperative treatment fails to adequately alleviate symptoms or sufficiently restore function in the athlete, hip arthroscopy can lead to improved pain, improved range of motion, and high rates of return to play with proper postoperative rehabilitation. The rate of return to previous level of competition is also high with accurate diagnosis and well-executed correction of deformity. A clear understanding of the etiology, diagnosis, management, and outcomes is essential for clinicians to optimally help patients to return to play. PMID:27543404

Anterior acetabular labral tears and anteriorhip pain may result from high anteriorly directed forces from the femur on the acetabulum. While providing more pushoff is known to decrease sagittal plane hip moments, it is unknown if this gait modification also decreases hip joint forces. The purpose of this study was to determine if increasing pushoff decreases hip joint forces. Nine healthy subjects walked on an instrumented force treadmill at 1.25 m/s under two walking conditions. For the natural condition, subjects were instructed to walk as they normally would. For the increased pushoff condition, subjects were instructed to "push more with your foot when you walk". We collected motion data of markers placed on the subjects' trunk and lower extremities to capture trunk and leg kinematics and ground reaction force data to determine joint moments. Data were processed in Visual3D to produce the inverse kinematics and model scaling files. In OpenSim, the generic gait model (Gait2392) was scaled to the subject, and hip joint forces were calculated for the femur on the acetabulum after computing the muscle activations necessary to reproduce the experimental data. The instruction to "push more with your foot when you walk" reduced the maximum hip flexion and extension moment compared to the natural condition. The average reduction in the hip joint forces were 12.5%, 3.2% and 9.6% in the anterior, superior and medial directions respectively and 2.3% for the net resultant force. Increasing pushoff may be an effective gait modification for people with anteriorhip pain. PMID:25468661

Anterior acetabular labral tears and anteriorhip pain may result from high anteriorly directed forces from the femur on the acetabulum. While providing more pushoff is known to decrease sagittal plane hip moments, it is unknown if this gait modification also decreases hip joint forces. The purpose of this study was to determine if increasing pushoff decreases hip joint forces. Nine healthy subjects walked on an instrumented force treadmill at 1.25 m/s under two walking conditions. For the natural condition, subjects were instructed to walk as they normally would. For the increased pushoff condition, subjects were instructed to “push more with your foot when you walk”. We collected motion data of markers placed on the subjects’ trunk and lower extremities to capture trunk and leg kinematics and ground reaction force data to determine joint moments. Data were processed in Visual 3D to produce the inverse kinematics and model scaling files. In OpenSim, the generic gait model (Gait2392) was scaled to the subject, and hip joint forces were calculated for the femur on the acetabulum after computing the muscle activations necessary to reproduce the experimental data. The instruction to “push more with your foot when you walk” reduced the maximum hip flexion and extension moment compared to the natural condition. The average reduction in the hip joint forces was 12.5%, 3.2% and 9.6% in the anterior, superior and medial directions respectively and 2.3% for the net resultant force. Increasing pushoff may be an effective gait modification for people with anteriorhip pain. PMID:25468661

Hip dysplasia (HD) is 1 of the major reasons of coxarthrosis. The goal of the treatment of HD by Tönnis triple pelvic osteotomy (TPAO) is to improve the function of hip joint while relieving pain, delaying and possibly preventing end-stage arthritis. The aim of this study is to compare the clinical and radiological results of TPAO to determine if previous surgery has a negative effect on TPAO.Patients operated with TPAO between 2005 and 2010, included in this study. Patients divided into 2 groups: primary acetabular dysplasia (PAD) and residual acetabular dysplasia (RAD). Prepostoperatively, hip range of motion, Harris hip score (HHS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) hip score, visual analog scores (VAS), impingement tests, and also the presence of Trendelenburg sign (TS) were investigated for clinical evaluation. For radiological analysis pre-postoperative, anterior-posterior (AP) pelvis and faux profile radiographs were used. Acetabular index, lateral center edge (LCE) angle, and Sharp angles were measured by AP pelvis; anterior center edge (ACE) angle were measured by faux profile radiography. All the clinical and radiological data of the groups were analyzed separately for the pre-postoperative scores also the amount of improvement in all parameters were analyzed.SPSS20 (SPSS Inc., Chicago, IL) was used for statistical analysis. Wilcoxon test, McNemar test, paired t tests, and Mann-Whitney U tests were used to compare the groups. P hip parameter. When the patient groups were evaluated as pre-postoperatively, more statistically significant parameters were found in the PAD group when compared with RAD group. Extension

This paper will discuss how the Kennedy Space Center intends to perform precision cleaning verification by Air/Water Impingement in lieu of chlorofluorocarbon-113 gravimetric nonvolatile residue analysis (NVR). Test results will be given that demonstrate the effectiveness of the Air/Water system. A brief discussion of the Total Carbon method via the use of a high temperature combustion analyzer will also be given. The necessary equipment for impingement will be shown along with other possible applications of this technology.

The use of hip arthroscopy, as a surgical technique, has increased significantly over the past ten years. The procedure has shown good and excellent results in symptom relief and function improvement for patients with femoro-acetabular impingement (FAI) and concurrent chondro-labral lesions. It is also a reliable method to correct the characteristic pathomorphologic alteration of FAI. However, surgical results are less successful among patients with advanced articular damage and secondary hip osteoarthritis. The aim of this article is to present some clinical and imagenological tools to discriminate the good candidates for arthroscopic FAI treatment from those who are not, due to extensive articular damage. PMID:27163082

Study Design: Case Report Background: Femoral acetabular impingement (FAI) has been implicated in the etiology of acetabular labral tears. The rehabilitation of younger athletes following arthroscopic surgery for FAI and labral tears is often complex and multifactorial. A paucity of evidence exists to describe the rehabilitation of younger athletes who have undergone arthroscopic hip surgery. Case Presentation: This case report describes a four-phase rehabilitation program for a high school football player who underwent hip arthroscopy with a labral repair and chondroplasty. Outcomes: The player returned to training for football 16 weeks later and at the 4 month follow-up was pain free with no signs of FAI. Discussion: There is little evidence regarding the rehabilitation of younger athletes who undergo arthroscopic hip surgery. This case study described a four phase rehabilitation program for a high school football player who underwent hip arthroscopy and labral repair. The patient achieved positive outcomes with a full return to athletic activity and football. The overall success of these patients depends on the appropriate surgical procedure and rehabilitation program. Key Words: Femoral acetabular impingement (FAI), hip, hipimpingement Level of evidence: 4-Case report PMID:22530192

Given the increasing number of total hip arthroplasty procedures being performed annually, it is imperative that orthopaedic surgeons understand factors responsible for instability. In order to treat this potentially complex problem, we recommend correctly classifying the type of instability present based on component position, abductor function, impingement, and polyethylene wear. Correct classification allows the treating surgeon to choose the appropriate revision option that ultimately will allow for the best potential outcome. PMID:26733640

The purpose of the current study was to identify and map the periarticular neural anatomy of the hip to optimize periarticular injection techniques in total hip arthroplasty. A literature review of common search engines was performed using terms associated with hip innervation and 17 met the inclusion criteria. The studies addressed both gross and microscopic neural anatomy of the human hip joint, and the findings summarize key areas of hip mechanoreceptors and free nerve endings to provide a framework for targeted periarticular hip infiltration. Grossly, the hip joint is supplied by the femoral, obturator, sciatic, and superior gluteal nerves, as well as the nerve to the quadratus femoris. The greatest concentration of sensory nerve endings and mechanoreceptors is found at the anteriorhip capsule, especially superiorly. The labrum is most highly innervated from the 10 to 2 o'clock position. After the cup and liner are placed, periarticular injections should be infiltrated toward the remnant labrum from 10 to 2 o'clock. Before stem insertion, the visible periosteum may then be injected circumferentially about the femur. The anterior and superior capsular tissue, if retained, is routinely infiltrated at the time of capsular repair. Depending on surgical approach, the fascia and incised soft tissue are infiltrated before final closure. PMID:26731384

AIM: To investigate the association between sports hernias and femoroacetabular impingement (FAI) in athletes. METHODS: PubMed, MEDLINE, CINAHL, Embase, Cochrane Controlled Trials Register, and Google Scholar databases were electronically searched for articles relating to sports hernia, athletic pubalgia, groin pain, long-standing adductor-related groin pain, Gilmore groin, adductor pain syndrome, and FAI. The initial search identified 196 studies, of which only articles reporting on the association of sports hernia and FAI or laparoscopic treatment of sports hernia were selected for systematic review. Finally, 24 studies were reviewed to evaluate the prevalence of FAI in cases of sports hernia and examine treatment outcomes and evidence for a common underlying pathogenic mechanism. RESULTS: FAI has been reported in as few as 12% to as high as 94% of patients with sports hernias, athletic pubalgia or adductor-related groin pain. Cam-type impingement is proposed to lead to increased symphyseal motion with overload on the surrounding extra-articular structures and muscle, which can result in the development of sports hernia and athletic pubalgia. Laparoscopic repair of sports hernias, via either the transabdominal preperitoneal or extraperitoneal approach, has a high success rate and earlier recovery of full sports activity compared to open surgery or conservative treatment. For patients with FAI and sports hernia, the surgical management of both pathologies is more effective than sports pubalgia treatment or hip arthroscopy alone (89% vs 33% of cases). As sports hernias and FAI are typically treated by general and orthopedic surgeons, respectively, a multidisciplinary approach for diagnosis and treatment is recommended for optimal treatment of patients with these injuries. CONCLUSION: The restriction in range of motion due to FAI likely contributes to sports hernias; therefore, surgical treatment of both pathologies represents an optimal therapy. PMID:26380829

Surgery for femoroacetabular impingement (FAI) has been advocated for correction of cam and pincer hip joint morphology. Surgery for FAI was first pioneered by Myers et al, who surgically treated FAI by open dislocation. Arthroscopy was then introduced in 2005 by Sampson. Arthroscopy has continued to develop since then, with the intent of providing pain relief and improving function in patients with FAI. This Viewpoint discusses the escalating popularity of FAI surgery, the widespread acceptance of this relatively new surgical procedure, and next steps for determination of who benefits from this treatment. J Orthop Sports Phys Ther 2016;46(6):406-408. doi:10.2519/jospt.2016.0605. PMID:27245488

Abstract Many treatments for shoulder impingement syndrome (SIS) are available in clinical practice; some of which have already been compared with other treatments by various investigators. However, a comprehensive treatment comparison is lacking. Several widely used electronic databases were searched for eligible studies. The outcome measurements were the pain score and the Constant–Murley score (CMS). Direct comparisons were performed using the conventional pair-wise meta-analysis method, while a network meta-analysis based on the Bayesian model was used to calculate the results of all potentially possible comparisons and rank probabilities. Included in the meta-analysis procedure were 33 randomized controlled trials involving 2300 patients. Good agreement was demonstrated between the results of the pair-wise meta-analyses and the network meta-analyses. Regarding nonoperative treatments, with respect to the pain score, combined treatments composed of exercise and other therapies tended to yield better effects than single-intervention therapies. Localized drug injections that were combined with exercise showed better treatment effects than any other treatments, whereas worse effects were observed when such injections were used alone. Regarding the CMS, most combined treatments based on exercise also demonstrated better effects than exercise alone. Regarding surgical treatments, according to the pain score and the CMS, arthroscopic subacromial decompression (ASD) together with treatments derived from it, such as ASD combined with radiofrequency and arthroscopic bursectomy, showed better effects than open subacromial decompression (OSD) and OSD combined with the injection of platelet-leukocyte gel. Exercise therapy also demonstrated good performance. Results for inconsistency, sensitivity analysis, and meta-regression all supported the robustness and reliability of these network meta-analyses. Exercise and other exercise-based therapies, such as kinesio taping

A study examining impinging liquid jets has been underway to determine physical mechanisms responsible for combustion instabilities in liquid bi-propellant rocket engines. Primary atomization has been identified as an important process. Measurements of atomization length, wave structure, and drop size and velocity distribution were made under various ambient conditions. Test parameters included geometric effects and flow effects. It was observed that pre-impingement jet conditions, specifically whether they were laminar or turbulent, had the major effect on primary atomization. Comparison of the measurements with results from a two dimensional linear aerodynamic stability model of a thinning, viscous sheet were made. Measured turbulent impinging jet characteristics were contrary to model predictions; the structure of waves generated near the point of jet impingement were dependent primarily on jet diameter and independent of jet velocity. It has been postulated that these impact waves are related to pressure and momentum fluctuations near the impingement region and control the eventual disintegration of the liquid sheet into ligaments. Examination of the temporal characteristics of primary atomization (ligament shedding frequency) strongly suggests that the periodic nature of primary atomization is a key process in combustion instability.

Gas turbine engine technology is constantly challenged to operate at higher combustor outlet temperatures. In a modern gas turbine engine, these temperatures can exceed the blade and disk material limits by 600 F or more, necessitating both internal and film cooling schemes in addition to the use of thermal barrier coatings. Internal convective cooling is inadequate in many blade locations, and both internal and film cooling approaches can lead to significant performance penalties in the engine. Micro Cooling Concepts, Inc., has developed a turbine blade cooling concept that provides enhanced internal impingement cooling effectiveness via the use of microstructured impingement surfaces. These surfaces significantly increase the cooling capability of the impinging flow, as compared to a conventional untextured surface. This approach can be combined with microchannel cooling and external film cooling to tailor the cooling capability per the external heating profile. The cooling system then can be optimized to minimize impact on engine performance.

Of the many factors influencing the performance of a Stirling engine, that of transferring the combustion gas heat into the working fluid is crucial. By utilizing the high heat transfer rates obtainable with a jet impingement heat transfer system, it is possible to reduce the flame temperature required for engine operation. Also, the required amount of heater tube surface area may be reduced, resulting in a decrease in the engine nonswept volume and a related increase in engine efficiency. A jet impingement heat transfer system was designed by Rasor Associates, Inc., and tested in the GPU-3 Stirling engine at the NASA Lewis Research Center. For a small penalty in pumping power (less than 0.5% of engine output) the jet impingement heat transfer system provided a higher combustion-gas-side heat transfer coefficient and a smoothing of heater temperature profiles resulting in lower combustion system temperatures and a 5 to 8% increase in engine power output and efficiency.

Hip pain can have multiple causes, including intra-articular, juxta-articular, and referred pain, mainly from spine or sacroiliac joints. In this review, we discuss the causes of intra-articular hip pain from childhood to adulthood and the role of the appropriate imaging techniques according to clinical suspicion and age of the patient. Stress is put on the findings of radiographs, currently considered the first imaging technique, not only in older people with degenerative disease but also in young people without osteoarthritis. In this case plain radiography allows categorization of the hip as normal or dysplastic or with impingement signs, pincer, cam, or a combination of both. PMID:26885391

A turbine stator vane for an industrial engine, the vane having two impingement cooling inserts that produce a series of impingement cooling from the pressure side to the suction side of the vane walls. Each insert includes a spar with a row of alternating impingement cooling channels and return air channels extending in a radial direction. Impingement cooling plates cover the two sides of the insert and having rows of impingement cooling holes aligned with the impingement cooling channels and return air openings aligned with the return air channel.

The current conventional portals for hip arthroscopic surgery are the anterior, anterolateral, and posterolateral portals. For lesions in the medial anteroinferior or posteroinferior portion of the hip, these portals provide insufficient access to the lesion and consequently lead to incomplete treatment. Thus, in such a situation, a medial portal approach might be helpful. However, operators have avoided this procedure because of the risk of injury to the obturator, femoral neurovascular structures, and the medial femoral circumflex artery. Thus, to overcome the disadvantages of the conventional method for medial lesions of the hip, we performed a cadaveric study to evaluate the technique, usefulness, and risk of the medial portal technique. PMID:26330964

The dependence of far field acoustic measurements for a uniform jet on nozzle to plate spacing for small dimensionless spacings (h/d - 0.75 to 3.0) was investigated. Spectra from a real time analyzer were read and processed by an HP 2116 minicomputer in on-line mode. Similar data was generated for a fully developed pipe flow exit condition jet to compare with other investigations. The data base for normal jet impingement was extended to smaller values of nozzle to plate spacing. The effects of slight noise heating (30 deg rise) of the jet on the far field noise produced by the impinging jet are demonstrated.

Shoulder impingement is a progressive orthopedic condition that occurs as a result of altered biomechanics and/or structural abnormalities. An effective nonoperative treatment for impingement syndrome is aimed at addressing the underlying causative factor or factors that are identified after a complete and thorough evaluation. The clinician devises an effective rehabilitation program to regain full glenohumeral range of motion, reestablish dynamic rotator cuff stability, and implement a progression of resistive exercises to fully restore strength and local muscular endurance in the rotator cuff and scapular stabilizers. The clinician can introduce stresses and forces via sport-specific drills and functional activities to allow a return to activity. PMID:24648778

... this page: //medlineplus.gov/ency/presentations/100006.htm Hip joint replacement - series—Normal anatomy To use the sharing ... to slide 5 out of 5 Overview The hip joint is made up of two major parts: the ...

... this page: //medlineplus.gov/ency/article/007633.htm Hip joint injection To use the sharing features on this ... injection is a shot of medicine into the hip joint. The medicine helps relieve pain and inflammation. It ...

... this page: //medlineplus.gov/ency/article/002975.htm Hip joint replacement To use the sharing features on this page, please enable JavaScript. Hip joint replacement is surgery to replace all or part ...

... or falling can all sometimes lead to hip injuries. These include Strains Bursitis Dislocations Fractures Certain diseases also lead to hip injuries or problems. Osteoarthritis can cause pain and limited ...

The use of hip arthroscopy is gaining popularity for diagnostic and therapeutic purposes. With our increasing understanding of hip biomechanics and pathophysiology, our techniques for treatment are evolving as well. The main aim is to preserve the joint and prolong the degenerative process associated with femoroacetabular impingement (FAI). In general, combined pathology is encountered when a diagnosis of FAI is established. In our experience, we have seen large number of patients with a combination of cam and pincer lesions with or without associated labral tears. It is optimal to address all symptomatic pathology with one surgical intervention. The described technique shows the feasibility of dealing with the hip FAI pathology by using traction sutures on the capsule through a 2-portal technique. PMID:25264515

Background: The relationships between hip abductor and extensor strength and frontal plane hip and knee motions that are associated with anterior cruciate ligament injury risk are equivocal. However, previous research on these relationships has evaluated relatively low-level movement tasks and peak torque rather than a time-critical strength measure such as the rate of torque development (RTD). Hypothesis: Females with greater hip abduction and extension RTD would exhibit lesser frontal plane hip and knee motion during a single-leg jump-cutting task. Study Design: Descriptive laboratory study. Methods: Forty recreationally active females performed maximal isometric contractions and single-leg jump-cuts. From recorded torque data, hip extension and abduction RTD was calculated from torque onset to 200 ms after onset. Three-dimensional motion analysis was used to quantify frontal plane hip and knee kinematics during the movement task. For each RTD measure, jump-cut biomechanics were compared between participants in the highest (high) and lowest (low) RTD tertiles. Results: No differences in frontal plane hip and knee kinematics were identified between high and low hip abduction RTD groups. However, those in the high hip extension RTD group exhibited lower hip adduction (high, 3.8° ± 3.0°; low, 6.5° ± 3.0°; P = .019) and knee valgus (high, –2.5° ± 2.3°; low, –4.4° ± 3.2°; P = .046) displacements during the jump-cut. Conclusion: In movements such as cutting that are performed with the hip in a relatively abducted and flexed position, the ability of the gluteus medius to control hip adduction may be compromised. However, the gluteus maximus, functioning as a hip abductor, may take on a pivotal role in controlling hip adduction and knee valgus motion during these types of tasks. Clinical Relevance: Training with a specific emphasis on increasing explosive strength of the hip extensors may be a means through which to improve frontal plane hip and knee

The theoretical basis of the sonic-flow impinger is discussed. Details are given for the design, prediction of performance, preliminary evaluation for particle collection, and field use of a sonic-flow impinger train. (DT)

Abstract Hip dysplasia (HD) is 1 of the major reasons of coxarthrosis. The goal of the treatment of HD by Tönnis triple pelvic osteotomy (TPAO) is to improve the function of hip joint while relieving pain, delaying and possibly preventing end-stage arthritis. The aim of this study is to compare the clinical and radiological results of TPAO to determine if previous surgery has a negative effect on TPAO. Patients operated with TPAO between 2005 and 2010, included in this study. Patients divided into 2 groups: primary acetabular dysplasia (PAD) and residual acetabular dysplasia (RAD). Prepostoperatively, hip range of motion, Harris hip score (HHS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) hip score, visual analog scores (VAS), impingement tests, and also the presence of Trendelenburg sign (TS) were investigated for clinical evaluation. For radiological analysis pre–postoperative, anterior–posterior (AP) pelvis and faux profile radiographs were used. Acetabular index, lateral center edge (LCE) angle, and Sharp angles were measured by AP pelvis; anterior center edge (ACE) angle were measured by faux profile radiography. All the clinical and radiological data of the groups were analyzed separately for the pre–postoperative scores also the amount of improvement in all parameters were analyzed. SPSS20 (SPSS Inc., Chicago, IL) was used for statistical analysis. Wilcoxon test, McNemar test, paired t tests, and Mann–Whitney U tests were used to compare the groups. P hip parameter. When the patient groups were evaluated as pre–postoperatively, more statistically significant parameters were found in the PAD group when compared with RAD

The authors describe two cases of subacromial impingement syndrome of the shoulder secondary to scapular dyskinesia caused by a tumor in young adults. The two tumors, an osteochondroma and a ganglion, were located in the scapulothoracic joint and inhibited normal kinesis of the scapula during arm motion. PMID:22127513

.org Shoulder Impingement/Rotator Cuﬀ Tendinitis Page ( 1 ) One of the most common physical complaints is shoulder pain. Your shoulder is made up of several ... is vulnerable to many diﬀerent problems. The rotator cuﬀ is a frequent source of pain in the ...

Objective The purpose of this manuscript is to review current knowledge of how muscle activation and force production contribute to shoulder kinematics in healthy subjects and persons with shoulder impingement. Results The middle and lower serratus anterior muscles produce scapular upward rotation, posterior tilting, and external rotation. Upper trapezius produces clavicular elevation and retraction. The middle trapezius is primarily a medial stabilizer of the scapula. The lower trapezius assists in medial stabilization and upward rotation of the scapula. The pectoralis minor is aligned to resist normal rotations of the scapula during arm elevation. The rotator cuff is critical to stabilization and prevention of excess superior translation of the humeral head, as well as production of glenohumeral external rotation during arm elevation. Alterations in activation amplitude or timing have been identified across various investigations of subjects with shoulder impingement as compared to healthy controls. These include decreased activation of the middle or lower serratus anterior and rotator cuff, delayed activation of middle and lower trapezius, and increased activation of the upper trapezius and middle deltoid in impingement subjects. In addition, subjects with a short resting length of the pectoralis minor exhibit altered scapular kinematic patterns similar to those found in persons with shoulder impingement. Conclusion These normal muscle functional capabilities and alterations in patient populations should be considered when planning exercise approaches for the rehabilitation of these patients. PMID:20411160

Femoroacetabular impingement stems from an abnormal shape of the acetabulum and proximal femur. It is treated by resection of damaged soft tissue and by the shaping of bone to resemble normal features. The arthroscopic treatment of femoroacetabular impingement has many advantages, including minimal incisions, rapid recovery, and less pain. However, in some cases, revision is needed owing to the insufficient resection of damaged bone from a misreading of the surgical site. The limited view of arthroscopy is the major reason for the complications. In this research, a navigation method for the arthroscopic treatment of femoroacetabular impingement is developed. The proposed navigation system consists of femur attachable measurement device and user interface. The bone mounted measurement devices measure points on head-neck junction for registration and position of surgical instrument. User interface shows the three-dimensional model of patient's femur and surgical instrument position that is tracked by measurement device. Surgeon can know the three-dimensional anatomical structure of hip joint and surgical instrument position on surgical site using navigation system. Surface registration was used to obtain relation between patient's coordinate at the surgical site and coordinate of three-dimensional model of femur. In this research, we evaluated the proposed navigation system using plastic model bone. It is expected that the surgical tool tracking position accuracy will be less than 1 mm.

Restoration of equal leg lengths and dynamic hip stability are essential elements of a successful total hip arthroplasty. A careful clinical examination, a preoperative plan, and appropriate intraoperative techniques are necessary to achieve these goals. Preoperative identification of patients at risk for residual leg length discrepancy allows surgeons to adjust the surgical approach and/or the type of implant and provide better preoperative patient education. The use of larger femoral heads, high-offset stem options, and enhanced soft-tissue repairs have improved impingement-free range of motion as well as dynamic hip stability and have contributed to an overall reduction in dislocation. Methods for accurate leg length restoration and component positioning include anatomic landmarks, intraoperative radiographs, intraoperative calipers, stability testing, and computer-assisted surgery. If recurrent instability occurs after total hip arthroplasty, the underlying cause for dislocation should be identified and treated; this may include the use of semiconstrained dual-mobility or fully constrained liners, depending on abductor function. Surgeons should be aware of the clinical and surgical techniques for achieving leg length equalization and dynamic hip stability in total hip arthroplasty. PMID:27049193

Athletic injuries in or around the hip in the adolescent athlete encompass possible causes such as a single, traumatic event to those of repetitive microtrauma. The injuries may involve the bone or the soft tissues, with former involving the epiphysis, apophysis, metaphysis, or diaphysis, whereas the latter includes muscles and tendons. With the improvements in surgical technique and instrumentation for hip arthroscopy and the development of magnetic resonance arthrography, clinicians have been able to diagnose and treat labral tears, hip instability, snapping hip, loose bodies, chondral injuries, and femoroacetabular impingement. The clinician needs to consider acquired conditions that may have coincidentally become apparent as a result of the adolescent's participation in an organized sports program. These include slipped capital femoral epiphysis, Legg-Calvé-Perthes disease, and pathologic lesions and fractures. This study reviews the more common acute and chronic overuse injuries in or around the hip in the adolescent athlete and discusses hip injury prevention in this active patient population. PMID:21293240

The use of joint-preserving surgery of the hip has been largely abandoned since the introduction of total hip replacement. However, with the modification of such techniques as pelvic osteotomy, and the introduction of intracapsular procedures such as surgical hip dislocation and arthroscopy, previously unexpected options for the surgical treatment of sequelae of childhood conditions, including developmental dysplasia of the hip, slipped upper femoral epiphysis and Perthes' disease, have become available. Moreover, femoroacetabular impingement has been identified as a significant aetiological factor in the development of osteoarthritis in many hips previously considered to suffer from primary osteoarthritis. As mechanical causes of degenerative joint disease are now recognised earlier in the disease process, these techniques may be used to decelerate or even prevent progression to osteoarthritis. We review the recent development of these concepts and the associated surgical techniques. PMID:24395304

There have been a small number of case reports describing late normal-hip dislocations in children who were later diagnosed with developmental dysplasia of the hip. Here, we contest the assumption that normal hips can dislocate. We argue that (as in our case) the ultrasound scans in all published case reports on late dislocated normal hips did not show results that were entirely normal and therefore, so far, there has been no convincing evidence of a dislocation of a normal hip. We also want to highlight the importance of meticulous ultrasound and clinical assessments of high-risk children by an experienced orthopaedic surgeon. PMID:25144883

The rate and. area of cloud droplet impingement on four bodies of revolution were obtained experimentally in the NACA Lewis icing tunnel with a dye-tracer technique. The study included spheres, ellipsoidal forebodies of fineness ratios of 2.5 and 3.0, and a conical forebody of 300 included angle and covered a range of angles of attack from 0? to 60 and rotational speeds up to 1200 rpm. The data were obtained at an airspeed of 157 knots and are correlated by dimensionless impingement parameters. In general, the experimental data show that the local and total impingement rates and impingement limits of bodies of revolution are primarily functions of the modified inertia parameters, the body shape, and fineness ratio. Both the local impingement rate and impingement limits depend upon the angle of attack. Rotation of the bodies had a negligible effect on the impingement characteristics except for an averaging effect at angle of attack. For comparable diameters the bluffer bodies had the largest total impingement efficiency, but the finer and sharper bodies had the largest values of maximum local impingement efficiency and, in most cases, the largest limits of impingement. In most cases, the impingement characteristics were less than those calculated from theoretical trajectories; in general, however, fairly good agreement was obtained between the experimental and theoretical impingement characteristics.

This case outlines the phacoemulsification technique used to overcome the challenge of the hyperdeep anterior chamber, weak zonules, abnormal anterior capsule, and large capsular bag. Key steps included trypan blue staining of the anterior capsule, a large capsulorhexis, prolapse of the nucleus into the anterior chamber with phacoemulsification anterior to the capsulorhexis, and a posterior chamber-placed iris-clip intraocular lens. Successful visual rehabilitation is achievable in these anatomically challenging eyes. PMID:16857490

Reported rates of dislocation in hip hemiarthroplasty (HA) for the treatment of intra-capsular fractures of the hip, range between 1% and 10%. HA is frequently performed through a direct lateral surgical approach. The aim of this study is to determine the contribution of the anterior capsule to the stability of a cemented HA through a direct lateral approach. A total of five whole-body cadavers were thawed at room temperature, providing ten hip joints for investigation. A Thompson HA was cemented in place via a direct lateral approach. The cadavers were then positioned supine, both knee joints were disarticulated and a digital torque wrench was attached to the femur using a circular frame with three half pins. The wrench applied an external rotation force with the hip in extension to allow the hip to dislocate anteriorly. Each hip was dislocated twice; once with a capsular repair and once without repairing the capsule. Stratified sampling ensured the order in which this was performed was alternated for the paired hips on each cadaver. Comparing peak torque force in hips with the capsule repaired and peak torque force in hips without repair of the capsule, revealed a significant difference between the 'capsule repaired' (mean 22.96 Nm, standard deviation (sd) 4.61) and the 'capsule not repaired' group (mean 5.6 Nm, sd 2.81) (p < 0.001). Capsular repair may help reduce the risk of hip dislocation following HA. PMID:25568428

Objectives: This study aimed to assess gait and squat biomechanics 6-months following arthroscopic surgery for femoroacetabular impingement. Methods: Symptomatic patients with clinical and radiographic diagnosis of FAI who had failed non-operative treatment underwent gait and squat analysis preoperatively and at 6-months postoperatively following arthroscopic surgery for FAI. Age- and BMI-matched controls without radiographic FAI or other lumbar or lower extremity pathology underwent a single analysis for comparison. Comparisons between preoperative and 6-month postoperative gait and squat parameters as well as comparison to the control group were performed using paired and independent sample t-tests. Statistical significance was set at p<0.05. Results: Fifteen FAI patients and 9 controls were analyzed. Age for the patients vs. controls was 28.7±9.6 y vs. 27.8±6.5 y (p>0.05), respectively; while BMI was 23.5±5.1 kg/m2 vs. 22.8±3.5 kg/m2 (p>0.05). All gait parameters were unchanged between preoperative and 6-month postoperative testing (p>0.05), with a trend toward significance for hip external rotation moment (p=0.056) (Table 1). Squat testing revealed that FAI arthroscopic surgery increased maximum hip extension (p=0.011), with a trend toward significance for hip adduction moment (p=0.059). All other squat parameters did not differ from preoperative to 6-month follow-up (p>0.05). Compared to the control group, preoperative FAI patients had reduced hip external rotation moment during gait (p=0.024), with a trend toward significance for hip abduction moment (p=0.082). No other gait or squat differences were detected between FAI patients preoperatively or 6-months postoperatively compared to controls (p>0.05). Conclusion: Biomechanical gait and squat analysis at 6-month follow-up from arthroscopic FAI surgery revealed a tendency to improve external hip rotation during gait and maximum hip extension and hip adduction during squat. Arthroscopic surgery for FAI may

Experiments with vortex rings impinging permeable and solid boundaries are presented in order to investigate the influence of permeability. Utilizing Particle Image Velocimetry, we compared the behaviour of a vortex ring impinging four different reticulated foams (with permeability k ˜ 26 - 85 × 10-8 m2) and a solid boundary. Results show how permeability affects the stretching phenomena of the vortex ring and the formation and evolution of the secondary vortex ring with opposite sign. Moreover, permeability also affects the macroscopic no-slip boundary condition found on the solid boundary, turning it into an apparent slip boundary condition for the most permeable boundary. The apparent slip-boundary condition and the flux exchange between the ambient fluid and the foam are jointly responsible for both the modified formation of the secondary vortex and changes on the vortex ring diameter increase.

The medial approach to the hip via the adductors, as described by Ludloff or Ferguson, provides restricted visualization and incurs a risk of neurovascular lesion. We describe a minimally invasive medial hip approach providing broader exposure of extra- and intra-articular elements in a space free of neurovascular structures. With the lower limb in a "frog-leg" position, the skin incision follows the adductor longus for 6cm and then the aponeurosis is incised. A slide plane between all the adductors and the aponeurosis is easily released by blunt dissection, with no interposed neurovascular elements. This gives access to the lesser trochanter, psoas tendon and inferior sides of the femoral neck and head, anterior wall of the acetabulum and labrum. We report a series of 56 cases, with no major complications: this approach allows treatment of iliopsoas muscle lesions and resection or filling of benign tumors of the cervical region and enables intra-articular surgery (arthrolysis, resection of osteophytes or foreign bodies, labral suture). PMID:25164350

With the development of hip joint preservation procedures, the use of hip arthroscopy has grown dramatically over the past decade. However, recent articles have reported cases of hip instability after hip arthroscopy. Little is known about the role of static and dynamic stabilizers on hip joint stability, but there are concerns that an extensile capsulotomy or capsulectomy, osteoplasty of the acetabulum and proximal femur, and labral detachment or debridement during hip arthroscopy could potentially compromise hip stability. The safety parameters for arthroscopic hip surgery have not yet been fully established, and techniques are being developed for labral refixation and capsular repair after arthroscopic treatment of femoroacetabular impingement in an attempt to decrease the chance of iatrogenic hip instability or microinstability. The surgical technique presented in this article may provide anatomic repair of both the labrum and capsule using a double-loaded suture anchor technique. We believe that this technique increases both operative efficiency and the strength of the overall repair, which may minimize the risk of iatrogenic hip instability after hip arthroscopy. PMID:23766998

The analytical approximate solution of a non-linear jet impingement flow model will be demonstrated. We will show that this is an improvement over the series approximation obtained via the Adomian decomposition method, which is itself, a powerful method for analysing non-linear differential equations. The results of these approximations will be compared to the Runge-Kutta approximation in order to demonstrate their validity.

In a turbine bucket having an airfoil portion and a root portion, with a substantially planar platform at an interface between the airfoil portion and root portion, a platform cooling arrangement including at least one bore in the root portion and at least one impingement cooling tube seated in the bore, the tube extending beyond the bore with an outlet in close proximity to a targeted area on an underside of the platform.

Thruster plume impingement on a surface comprised of small, loose particles may cause blast ejecta to be spread over a large area and possibly cause damage to the vehicle. For this reason it is important to study the effects of plume impingement and crater formation on surfaces like those found on the moon. Lunar soil, also known as regolith, is made up of fine granular particles on the order of 100 microns.i Whenever a vehicle lifts-off from such a surface, the exhaust plume from the main engine will cause the formation of a crater. This crater formation may cause laterally ejected mass to be deflected and possibly damage the vehicle. This study is a first attempt at analyzing the dynamics of crater formation due to thruster exhaust plume impingement during liftoff from the moon. Though soil erosion on the lunar surface is not considered, this study aims at examining the evolution of the shear stress along the lunar surface as the engine fires. The location of the regions of high shear stress will determine where the crater begins to form and will lend insight into how big the crater will be. This information will help determine the probability that something will strike the vehicle. The final sections of this report discuss a novel method for studying this problem that uses a volume of fluid (VOF)ii method to track the movement of both the exhaust plume and the eroding surface.

Experiments and CFD have been performed to study circular and elliptic jets in a submerged water jet facility. The tests included discharge coefficient measurement to evaluate pressure losses encountered in noncircular nozzles compared to circular ones. Three-dimensional pressure mappings on the impingement surface and PIV measurement of the jet mean and turbulent velocity have been performed at different compound impingement angles relative to the impingement surface and at different stand-off distances. The objective was to investigate the effect of the non-circular geometry on the flow field and on the impact region. The tests were performed in a close loop system in which the water was pumped through the nozzles into a clear Plexiglas tank. The Reynolds numbers were typically in the range of 250000. Discharge coefficients of the elliptic nozzle was somewhat lower than that of the circular jet but spreading rate and turbulence level were higher. Pressure mapping showed that the nozzle exit geometry had an effect on the pressure distribution in the impact region and that high-pressure zones were generated at specific impact points. PIV measurements showed that for a same total exit area, the elliptic jets affected a surface area that is 8the equivalent circular. The turbulence level in the elliptic jet tripled due to the nozzle design. Results of the CFD model were in good agreement with the experimental data.

We report the case of an osteoid osteoma in the dorsal talar neck of a healthy long-distance runner, masquerading as anterior ankle impingement syndrome. We discuss the diagnosis and successful treatment using percutaneous CT-guided laser photocoagulation. A concise review of the principles of the management of osteoid osteomas is also presented. PMID:24859559

Background: The amount of patients referred with longstanding, non-arthritic hip pain is increasing, as are the treatment options. Left untreated hip dysplasia, acetabular retroversion and femoroacetabular impingement (FAI) may lead to osteoarthritis (OA). Finding the right treatment option for the right patient can be challenging in patients with non-arthritic hip pain. Purpose: The purpose of this study was to categorize the radiographic findings seen in patients with longstanding hip pain, suspect for an intraarticular pathology, and provide a treatment algorithm allocating a specific treatment option for each clinical condition. Material and Methods: A review of the literature was performed using Public Medline searches of MeSH terms combined with synonyms for femoroacetabular impingement, acetabular retroversion, periacetabular osteotomy and hip arthroscopy. Results: Radiographic findings associated with acetabular retroversion described in the literature were the crossover sign, the posterior wall sign and the ischial spine sign, while Wiberg’s lateral center-edge angle (CE-angle) together with Leqeusne’s acetabular index indicate hip dysplasia. A Tönnis index >2 indicates osteoarthritis, however unsatisfying results are documented following joint preserving surgery with a Tönnis index >1. Furthermore, ischial spine sign in combination with the posterior wall sign indicates total acetabular retroversion prone to periacetabular osteotomy in contrast to focal retroversion prone to hip arthroscopy. These findings were used creating a treatment algorithm for intraarticular pathologies in patients with longstanding hip pain. Conclusion: Based on the radiographic findings, the algorithm presented in this study can be a helpful tool in the decision-making for the treatment of patients with non-arthritic hip pain, suspect for intraarticular pathologies. PMID:27583059

... inflammation and swelling of the tissues around the hip joint. Usually only one hip is affected. This condition ... to reduce the swelling and inflammation around the hip joint. Your child's doctor will probably ask you to ...

From 1980 to 1984, 72 patients with impingement syndrome were treated by anterior acromioplasty before they developed rotator cuff tears. Follow-up evaluations averaged 23 months (range, five to 48 months). The average age was 42 years (range, 23-61 years). Preoperatively, 80% of the patients had pain at rest; the other 20% complained of pain during moderate activity. At the time of follow-up examination, 89% showed significant improvement, while 11% remained unchanged. Thirty-seven percent of the patients had varying degrees of muscle weakness preoperatively; of these, 71% were improved, 21% were unchanged, and 8% had a further decrease in the range of motion postoperatively. The results indicate that anterior acromioplasty is an excellent procedure for relief of pain due to impingement. Additionally, beneficial results were obtained in range of motion and muscle strength. In only a few select cases was lateral clavicle excision or tenodesis of the long head of the biceps necessary. Caution is advised in allowing return to strenuous activity unless the patient has recovered adequate strength in the cuff musculature. PMID:3720075

Background: Femoroacetabular impingement is a debilitating hip condition commonly affecting athletes playing American football. The condition is associated with reduced hip range of motion; however, little is known about the range-of-motion demands of football athletes. This knowledge is critical to effective management of this condition. Purpose: To (1) develop a normative database of game-like hip and knee kinematics used by football athletes and (2) analyze kinematic data by playing position. The hypothesis was that kinematics would be similar between running backs and defensive backs and between wide receivers and quarterbacks, and that linemen would perform the activities with the most erect lower limb posture. Study Design: Descriptive laboratory study. Methods: Forty National Collegiate Athletic Association (NCAA) football athletes, representing 5 playing positions (quarterback, defensive back, running back, wide receiver, offensive lineman), executed game-like maneuvers while lower body kinematics were recorded via optical motion capture. Passive hip range of motion at 90° of hip flexion was assessed using a goniometer. Passive range of motion, athlete physical dimensions, hip function, and hip and knee rotations were submitted to 1-way analysis of variance to test for differences between playing positions. Correlations between maximal hip and knee kinematics and maximal hip kinematics and passive range of motion were also computed. Results: Hip and knee kinematics were similar across positions. Significant differences arose with linemen, who used lower maximal knee flexion (mean ± SD, 45.04° ± 7.27°) compared with running backs (61.20° ± 6.07°; P < .001) and wide receivers (54.67° ± 6.97°; P = .048) during the cut. No significant differences were found among positions for hip passive range of motion (overall means: 102° ± 15° [flexion]; 25° ± 9° [internal rotation]; 25° ± 8° [external rotation]). Several maximal hip measures were found

... problems that can lead to dislocation of the hip bones. This is also called dysplasia (say: "diss-play-see-uh"). This means that ... problems later in life? Source Screening for Developmental Dysplasia of the Hip by LM French, M.D., and FR Dietz, ...

... because the ball-like top of your thigh bone moves within a cup-like space in your pelvis. Your hips are very stable. When they are healthy, it takes great force to hurt them. However, playing sports, running, ... of the hip causes weak bones that break easily. Both of these are common ...

A normal hip has a natural tendency toward stability because of both osseous and soft tissue structures. Hip motion is primarily rotational around a center of rotation. When the femoral head and its center of rotation translate, with or without rotation, the inherent stability of the femoroacetabular articulation may be lost. The spectrum of hip instability ranges from subtle microinstability to traumatic dislocation. Microinstability may be the cause or the effect of several other hip pathologies. Soft tissue contributions to stability include the static capsule, dynamic musculotendinous units, and underlying generalized connective tissue (eg, Ehlers-Danlos). Osseous contributions include multiple femoral and acetabular radiographic coverage parameters. Iatrogenic contributions include an unrepaired capsulotomy, overresection of the acetabular rim (iatrogenic dysplasia), overresection of cam osteochondroplasty, iliopsoas tenotomy, labral debridement, and ligamentum teres debridement. Patients with hip microinstability often have deep groin pain, exhibited by a C sign. These patients frequently participate in flexibility sports and activities, such as ballet, gymnastics, figure skating, and martial arts. On physical examination, generalized hypermobility syndromes should be assessed, as should loss of log-roll external rotation recoil, excessive abduction, trochanteric-pelvic impingement, and abductor fatigue. Standard imaging, including plain radiographs, magnetic resonance imaging, and computed tomography, should be analyzed for all causes of hip pain. A new plain radiograph, the splits radiograph is introduced here, consistently showing lateral femoral head translation and creation of a vacuum sign, showing hip microinstability. The splits radiograph is illustrated in a 22-year-old female dancer who presented with bilateral deep anterolateral groin pain. PMID:26730687

In this in vitro study of the hip joint we examined which soft tissues act as primary and secondary passive rotational restraints when the hip joint is functionally loaded. A total of nine cadaveric left hips were mounted in a testing rig that allowed the application of forces, torques and rotations in all six degrees of freedom. The hip was rotated throughout a complete range of movement (ROM) and the contributions of the iliofemoral (medial and lateral arms), pubofemoral and ischiofemoral ligaments and the ligamentum teres to rotational restraint was determined by resecting a ligament and measuring the reduced torque required to achieve the same angular position as before resection. The contribution from the acetabular labrum was also measured. Each of the capsular ligaments acted as the primary hip rotation restraint somewhere within the complete ROM, and the ligamentum teres acted as a secondary restraint in high flexion, adduction and external rotation. The iliofemoral lateral arm and the ischiofemoral ligaments were primary restraints in two-thirds of the positions tested. Appreciation of the importance of these structures in preventing excessive hip rotation and subsequent impingement/instability may be relevant for surgeons undertaking both hip joint preserving surgery and hip arthroplasty. Cite this article: Bone Joint J 2015; 97-B:484–91. PMID:25820886

Introduction: This study aimed to determine the dislocation and reoperation rate, functional outcomes, and the survival rate of the unique subset of very old but lucid and independent patients with hip fractures following a total hip arthroplasty (THA) and geriatric team-coordinated perioperative care. Method: Between 2000 and 2006, previously independent ambulatory patients ≥80 years old presenting with an intracapsular hip fracture were given THAs under the care of an integrated orthopedic surgery–geriatric service. Their fracture-related complications, ambulation, mental status, and survival were followed for 5 to 11 years postinjury. Results: Five years postinjury, 57 (61.3%) patients of the original study group were living. In all, 3 (3.2%) patients had postoperative hip dislocations (and 2 patients had dislocation twice) and 2 reoperations were needed within the first postoperative month. There were no hip dislocations or reoperations after the first year. Radiographs obtained on 88% of the surviving patients at 5 years postoperatively showed that all remained unchanged from their immediate postoperative images. Nearly half of the patients were still able to ambulate as they did preoperatively and their mixed-model equation was statistically unchanged. Conclusion: This study of patients >80 years old with previously good functional status demonstrates that with appropriate surgical (best prosthesis, good operating technique, and regional anesthesia) and geriatric (pre- and postoperative assessments, close follow-up, medication adjustments, and fall-prevention instruction) care, they have few hip dislocations and reoperations, survive postfracture at least as long as their noninjured contemporaries, and continue to function and ambulate as they did prior to their injury. PMID:24660092

The intent of this report is to document a procedure used at LANL for HIP bonding aluminum cladding to U-10Mo fuel foils using a formed HIP can for the Domestic Reactor Conversion program in the NNSA Office of Material, Management and Minimization, and provide some details that may not have been published elsewhere. The HIP process is based on the procedures that have been used to develop the formed HIP can process, including the baseline process developed at Idaho National Laboratory (INL). The HIP bonding cladding process development is summarized in the listed references. Further iterations with Babcock & Wilcox (B&W) to refine the process to meet production and facility requirements is expected.

Starting from the wrong derivation by Erukhimovitch and Baram of an equation alternative to the classical Kolmogoroff-Johnson-Mehl-Avrami one for the transformed fraction in an infinite specimen, undergoing an isothermal first-order phase transformation, it is shown that a different exact solution of the geometrical problem of impingement can be obtained. Such solution is equivalent to the empirical one already presented by Austin and Rickett more than sixty years ago and allows to better fit experimental results for isothermal transformations. This also suggests that perhaps different statistical derivations could allow to reach the same result.

Posterior ankle pain can occur for many reasons. If it is produced by forced plantarflexion of the foot, it is often a result of impingement from an enlarged posterior talar process or an os trigonum. This condition may present in an acute or chronic state. Management is initially nonoperative, but surgical treatments are available. This condition is often seen in athletes, so procedures that limit surgical trauma and allow early return to activity are ideal. An arthroscopic approach for this disorder produces good outcomes with limited complications. Understanding the indications, local anatomy, and surgical technique, allows good, reproducible outcomes. PMID:27599438

The imager's role in diagnosing prearthritic hip syndromes has increased significantly in the past 10 years. As surgical and nonsurgical treatment algorithms for mechanical syndromes including femoroacetabular impingement and acetabular dysplasia have evolved, clinicians have grown increasingly dependent on radiography, MR imaging, MR arthrography, and even computed tomography to confirm diagnoses and support the need for potential intervention. Musculoskeletal radiologists should help referrers navigate available imaging options and protocols, while using both clinical information and imaging findings to arrive at a diagnosis that adds value to the treatment plan. PMID:27545428

Objective: We outline impingement entities, describe the history and physical examination, and provide an overview of treatment beyond that routinely used in glenohumeral and scapulothoracic dysfunction. Background: In the athlete, pain and dysfunction due to excessive overhead use or abnormal positioning of the shoulder is common and can result from multiple etiologies, including impingement syndromes. Primary, secondary, internal, and coracoid impingement have all been described. Description: These entities will be discussed, including pathology, evaluation, and treatment. Clinical Advantages: Incorporating a systematic evaluation and treatment of impingement syndromes optimizes care for the patient with shoulder pain. PMID:16558643

Posterosuperior glenoid internal impingement (PGII) is an impingement syndrome of the shoulder that is most commonly seen in the throwing or overhead athlete. The supraspinatus can be normally compressed or impinged between the greater tuberosity and the posterosuperior labrum in the abduction and external rotation position. However, repetitive throwing and biomechanical abnormalities may lead to the intensification of this contact and to the clinical and pathological picture of PGII. The injured athlete usually complains of poor throwing performance and pain located in the posterosuperior aspect of the shoulder. Two main theories regarding the aetiology of PGII have been postulated with differing initial mechanisms. The MRI features of PGII have been described and include supraspinatus and anterior infraspinatus partial undersurface tears, bony changes at the humeral head and labral pathology, including a variation of the type II superior labrum from anterior to posterior lesion. This pictorial essay aims to present cases illustrating the pathophysiology, clinical features and recently described MRI findings, and discuss some of the MR protocol considerations. PMID:25586665

Ideally, developmental dysplasia of the hip is treated early in childhood by nonsurgical methods. If these methods are ineffective, surgical reduction in a nonambulating child is required. A young child (age 6 to 18 months) who requires surgical reduction can be treated by formal anterior open reduction or by the medial Ludloff approach to the hip. Additional bony procedures are usually not required in these young patients. Delayed diagnosis is still common, requiring surgical reduction for children of walking age. These older children usually require formal open reduction (anterior approach) plus an associated bony osteotomy (acetabular, proximal femoral, or, in some cases, both types of osteotomies) to better stabilize the hip. The addition of a proximal femoral derotational shortening osteotomy for open reduction in older children was first used in children older than 3 years, but now it is commonly used in children as young as 2 years. This osteotomy decreases the forces on the reduced hip and minimizes the chances for redislocation and osteonecrosis. In all surgical procedures for developmental dysplasia of the hip, the surgeon must avoid too great a focus on bony osteotomies because the management of soft-tissue abnormalities is critical in achieving a stable reduction. PMID:24720317

Advanced MRI cartilage imaging such as T(1)-rho (T1ρ) for the diagnosis of early cartilage degradation prior to morpholgic radiological changes may provide prognostic information in the management of joint disease. This study aimed first to determine the normal T1ρ profile of cartilage within the hip, and secondly to identify any differences in T1ρ profile between the normal and symptomatic femoroacetabular impingement (FAI) hip. Ten patients with cam-type FAI (seven male and three female, mean age 35.9 years (28 to 48)) and ten control patients (four male and six female, mean age 30.6 years (22 to 35)) underwent 1.5T T1ρ MRI of a single hip. Mean T1ρ relaxation times for full thickness and each of the three equal cartilage thickness layers were calculated and compared between the groups. The mean T1ρ relaxation times for full cartilage thickness of control and FAI hips were similar (37.17 ms (SD 9.95) and 36.71 ms (SD 6.72), respectively). The control group demonstrated a T1ρ value trend, increasing from deep to superficial cartilage layers, with the middle third having significantly greater T1ρ relaxation values than the deepest third (p = 0.008). The FAI group demonstrated loss of this trend. The deepest third in the FAI group demonstrated greater T1ρ relaxation values than controls (p = 0.028). These results suggest that 1.5T T1ρ MRI can detect acetabular hyaline cartilage changes in patients with FAI. PMID:22933489

Background: Hip conditions, such as femoroacetabular impingement and labral injury, can cause pain and limit the ability to play sports at a professional level. Purpose: To evaluate performance metrics of professional golfers prior to arthroscopic hip surgery and after surgery. Study Design: Case series; Level of evidence, 4. Methods: This study included professional golfers who underwent arthroscopic hip surgery. Primary outcome variables were greens in regulation and driving distance. Metrics were recorded for 2 years prior to arthroscopic hip surgery and 1, 2, and 5 years after arthroscopy. Results: A consecutive cohort of 20 male professional golfers (27 hips) from 2000 to 2011 underwent arthroscopic hip surgery by a single surgeon. All players were on the PGA Tour with a mean age of 38 years (range, 26-54 years). Eleven hips had labral repair and 16 had labral debridements. Four hips required microfracture of a chondral lesion. All players returned to play at a mean of 4.7 months (range, 1 month to 2 years). The mean number of years played after surgery was 5.72. There was no significant difference between preoperative and postoperative greens in regulation (P = .227). The mean distance per golf drive was significantly longer at 1 and 2 years postoperative compared with prior to surgery (P < .01), and driving distance at 5 years was also longer than preoperative (P = .008). Conclusion: Arthroscopic management of chondrolabral dysfunction due to femoroacetabular impingement in the professional golfer allowed the golfer to return to the same skill level prior to surgery. Mean driving distance was found to increase after arthroscopy, demonstrating not only a return but also an improvement in driving performance from prior level of play. PMID:27141515

Rotator cuff disorders are considered to be among the most common causes of shoulder pain and disability encountered in both primary and secondary care. The general pathology of subacromial impingment generally relates to a chronic repetitive process in which the conjoint tendon of the rotator cuff undergoes repetitive compression and micro trauma as it passes under the coracoacromial arch. However acute traumatic injuries may also lead to this condition. Diagnosis remains a clinical one, however advances in imaging modalities have enabled clinicians to have an increased understanding of the pathological process. Ultrasound scanning appears to be a justifiable and cost effective assessment tool following plain radiographs in the assessment of shoulder impingment, with MRI scans being reserved for more complex cases. A period of observed conservative management including the use of NSAIDs, physiotherapy with or without the use of subacromial steroid injections is a well-established and accepted practice. However, in young patients or following any traumatic injury to the rotator cuff, surgery should be considered early. If surgery is to be performed this should be done arthroscopically and in the case of complete rotator cuff rupture the tendon should be repaired where possible. PMID:24082973

The problem of steady axisymmetric deformations of a liquid sessile drop on a flat solid surface under an impinging gas jet is of interest for understanding the fundamental behavior of free surface flows as well as for establishing the theoretical basis in process design for the Aerosol direct-write technology. It is studied here numerically using a Galerkin finite-element method, by computing solutions of Navier-Stokes equations. For effective material deposition in Aerosol printing, the desired value of Reynolds number for the laminar gas jet is found to be greater than ~500. The sessile drop can be severely deformed by an impinging gas jet when the capillary number is approaching a critical value beyond which no steady axisymmetric free surface deformation can exist. Solution branches in a parameter space show turning points at the critical values of capillary number, which typically indicate the onset of free surface shape instability. By tracking solution branches around turning points with an arc-length continuation algorithm, critical values of capillary number can be accurately determined. Near turning points, all the free surface profiles in various parameter settings take a common shape with a dimple at the center and bulge near the contact line. An empirical formula for the critical capillary number for sessile drops with contact angle is derived for typical ranges of jet Reynolds number and relative drop sizes especially pertinent to Aerosol printing.

"Subacromial impingement syndrome (SIS)" is often used as a diagnostic label, but has become more controversial as such in the literature. We assessed views on SIS in clinical practice using a survey with 63 0-10 VAS items among orthopedic surgeons and physical therapists from the United States and the Netherlands. Multivariate regression and cluster analyses were applied to identify consensus items and to study profession and/or nationality effects on item ratings. Most items received neutral or highly variable ratings. Twenty-nine were considered associated with SIS, including worsening of pain with overhead activities, painful arc and a positive Neer's test. Seven items were regarded pleading against SIS, including loss of passive motion. Activity modifications and physical therapy are the most important treatments according to therapists, who highly valued motion-related etiologic mechanisms. Surgeons, with higher ratings for intrinsic and anatomic etiologies, appreciated the use of subacromial corticosteroids and surgery. Clinicians from different professional backgrounds have different views on what SIS is, and even within professional groups, variations are substantial. This has to be taken into account when communicating about SIS symptoms, for example, in intercollegial consultation or scientific research. The authors suggest cautious use of (subacromial) impingement syndrome as a diagnostic label. PMID:23615729

Hip arthroscopy has continued to expand its horizons in treating many conditions other than femoroacetabular impingement (FAI). However, the results of hip arthroscopy are known to be poor if the degree of articular cartilage damage is significant. We wanted to assess, whether the procedure might have a role in the management of young and active patients with advanced osteoarthritis (OA) and whether it should be offered as a treatment modality. 77 consecutive patients with Tönnis grade 2 and 3 osteoarthritis of the hip who had undergone hip arthroscopy were included in the study. Patients' medical notes, plain radiographs and outcome scores (modified Harris hip score (mHHS), non-arthritic hip score (NAHS)) preoperatively and postoperatively at six weeks, six months, one year and annually thereafter, were analysed. 77 patients consisted of 63 men and 14 women with mean follow-up of 2.8 years (2.2 to 4.2) and mean age at surgery of 43 years (19 to 64). The mean preoperative mHHS and NAHS scores were 58 (28 to 87) and 64 (27 to 93) respectively. The mean improvements in both the mHHS and NAHS scores were significant (p = 0.003 and p = 0.0001 for mHHS at one and two years, p = 0.002 and p = 0.0003 for NAHS at one and two years, respectively). There were 34 patients (44%) who required a total hip replacement at mean of 18 months (6 to 48) after hip arthroscopy. We conclude that hip arthroscopy improves outcome scores in 56% of patients with severe OA of the hip (Tönnis grade 2 and 3) for at least two years after surgery. We thus consider the procedure to be a reasonable option for patients with hip OA, although success of the procedure will be less than if undertaken for certain other conditions. PMID:25635392

Objective: To detail the presentation of an elite male ice hockey goaltender with cam-type femoroacetabular impingement (FAI) and acetabular labral tears. This case will outline the prevalence, clinical presentation, imaging criteria, pathomechanics, and management of FAI, with specific emphasis on the ice hockey goaltender. Clinical Features: A 22-year old retired ice hockey goaltender presented to a chiropractor after being diagnosed by an orthopaedic surgeon with MRI confirmed left longitudinal and chondral flap acetabular labral tears and cam-type femoroacetabular impingement (FAI). As the patient was not a candidate for surgical intervention, a multimodal conservative treatment approach including manual therapy, electroacupuncture and rehabilitation exercises were implemented. Summary: FAI is prevalent in ice hockey players, particularly with goaltenders. Both skating and position-dependent hip joint mechanics involved in ice hockey may exacerbate or contribute to acquired and congenital forms of symptomatic FAI. As such, practitioners managing this population must address sport-specific demands in manual therapy, rehabilitation and physical training, to improve functional outcomes and prevent future injury. PMID:26816416

Several approaches may be used for hip replacement surgery either in combination with conventional total hip arthroplasty (THA) or resurfacing hip arthroplasty (RHA). This study investigates the differences in hip loading during gait one year or more after surgery in three cohorts presenting different surgical procedures, more specific RHA placed using the direct lateral (RHA-DLA, n=8) and posterolateral (RHA-PLA, n=14) approach as well as THA placed using the direct anterior (THA-DAA, n=12) approach. For the DAA and control subjects, hip loading was also evaluated during stair ascent and descent to evaluate whether these motions can better discriminate between patients and controls compared to gait. Musculoskeletal modelling in OpenSim was used to calculate in vivo joint loading. Results showed that for all operated patients, regardless the surgical procedure, hip loading was decreased compared to control subjects, while no differences were found between patient groups. This indicates that THA via DAA results in similar hip loading as a RHA via DLA or PLA. Stair climbing did not result in more distinct differences in hip contact force magnitude between patients and controls, although differences in orientation were more distinct. However, patients after hip surgery did adjust their motion pattern to decrease the magnitude of loading on the hip joint compared to control subjects. PMID:27004636

Objective Hip arthroscopy in the setting of hip dysplasia is controversial in the orthopaedic community, as the outcome literature has been variable and inconclusive. We hypothesise that outcomes of hip arthroscopy may be diminished in the setting of hip dysplasia, but outcomes may be acceptable in milder or borderline cases of hip dysplasia. Methods A systematic search was performed in duplicate for studies investigating the outcome of hip arthroscopy in the setting of hip dysplasia up to July 2015. Study parameters including sample size, definition of dysplasia, outcomes measures, and re-operation rates were obtained. Furthermore, the levels of evidence of studies were collected and quality assessment was performed. Results The systematic review identified 18 studies investigating hip arthroscopy in the setting of hip dysplasia, with 889 included patients. Criteria used by the studies to diagnose hip dysplasia and borderline hip dysplasia included centre edge angle in 72% of studies but the range of angles were quite variable. Although 89% of studies reported improved post-operative outcome scores in the setting of hip dysplasia, revision rates were considerable (14.1%), with 9.6% requiring conversion to total hip arthroplasty. Conclusion The available orthopaedic literature suggests that although improved outcomes are seen in hip arthroscopy in the setting of hip dysplasia, there is a high rate of re-operation and conversion to total hip arthroplasty. Furthermore, the criteria used to define hip dysplasia vary considerably among published studies. Cite this article: M. Yeung, M. Kowalczuk, N. Simunovic, O. R. Ayeni. Hip arthroscopy in the setting of hip dysplasia: A systematic review. Bone Joint Res 2016;5:225–231. DOI: 10.1302/2046-3758.56.2000533. PMID:27313136

Large eddy simulation and particle image velocimetry measurements have been performed to evaluate the characteristics of a turbulent impinging jet with large nozzle height-to-diameter ratio (H/D = 20). The Reynolds number considered is approximately 28 000 based on the jet exit velocity and nozzle diameter. Mean normalized centerline velocity in both the free jet and impingement regions and pressure distribution over the plate obtained from simulations and experiments show good agreement. The ring-like vortices generated due to the Kelvin-Helmholtz instabilities at the exit of the nozzle merge, break down and transform into large scale structures while traveling towards the impingement plate. A Strouhal number of 0.63 was found for the vortices generated at the exit of the nozzle. However, this parameter is reduced along the centerline towards the impingement zone. A characteristic frequency was also determined for the large scale structures impinging on the plate. The expansion, growth, tilt, and three-dimensionality of the impinging structures cause dislocation of the impinging flow from the centerline, which is significantly larger when compared with flows having small H/D ratios. Contrary to the behavior of impinging jets with small stand-off distance, due to the loss of coherence, the large scale structures do not result in significant secondary vortices in the wall jet region and consequently less fluctuations were observed for wall shear stress.

During the process of impingement on cooling system intake screens, fish may be subject to different types of stress, the total of which often results in the death of individual fish. This report assesses the use of occult hemoglobin in fish demand mucus as an indicator of impingement stress. (ACR)

... hemiarthroplasty to replace the ball part of your hip joint. You should have received physical therapy while you were in the hospital or at a rehabilitation center before going home from the hospital.

... hip area, and images are recorded on a computer. The black-and-white images show the internal ... the images can be seen clearly on the computer screen. A technician (sonographer) trained in ultrasound imaging ...

... such as sprinting, kicking, and changing direction while running or moving, can stretch and tear the hip flexors. Runners, people who do martial arts, and football, soccer, and hockey players are more likely to have ...

Hip dysplasia is a common orthopaedic developmental disorder of dogs. This paper reviews the treatment options available for management of the condition in the skeletally immature and adult dog. PMID:21906059

Epidemiological evidence points strongly to a hazard of hip osteoarthritis from heavy manual work. Harmful exposures may be reduced by the elimination or redesign of processes and the use of mechanical aids. Reducing obesity might help to protect workers whose need to perform heavy lifting cannot be eliminated. Particularly high relative risks have been reported in farmers, and hip osteoarthritis is a prescribed occupational disease in the UK for long-term employees in agriculture. Even where it is not attributable to employment, hip osteoarthritis impacts importantly on the capacity to work. Factors that may influence work participation include the severity of disease, the physical demands of the job, age and the size of the employer. Published research does not provide a strong guide to the timing of return to work following hip arthroplasty for osteoarthritis, and it is unclear whether patients should avoid heavy manual tasks in their future employment. PMID:26612242

Epidemiological evidence points strongly to a hazard of hip osteoarthritis from heavy manual work. Harmful exposures may be reduced by elimination or redesign of processes and use of mechanical aids. Reducing obesity might help to protect workers whose need to perform heavy lifting cannot be eliminated. Particularly high relative risks have been reported in farmers, and hip osteoarthritis is a prescribed occupational disease in the UK for long-term employees in agriculture. Even where it is not attributable to employment, hip osteoarthritis impacts importantly on capacity to work. Factors that may influence work participation include the severity of disease, the physical demands of the job, age, and the size of the employer. Published research does not provide a strong guide to the timing of return to work following hip arthroplasty for osteoarthritis, and it is unclear whether patients should avoid heavy manual tasks in their future employment. PMID:26612242

The treatment of the spastic hip in Cerebral Palsy (CP) remains a challenge especially in cases of advance changes. Many options are available and the key for a good outcome is to find the best surgical procedure to an individualized patient. The hip fusion is one of the surgical options. The authors presented a group of spastic CP with painful chronic hip subluxation and dislocation treated with hip fusion with a mean follow-up period of 14.5 years. Surgical technique, post-operative management and outcomes were shown, also with the observations done regarding the evolution of the contralateral hip after the hip fusion. They concluded that the hip arthrodesis is an option for patients with spastic CP with painful subluxation or dislocated hips with the goal of pain relief maintain or improve functional status, and facilitating the care. The best candidate is a young ambulatory patient with normal contralateral hip and normal spinal alignment. PMID:25207734

Total hip arthroplasty (THA) has revolutionized the treatment of hip arthritis. A number of surgical approaches to the hip joint exist, each with unique advantages and disadvantages. The most commonly used approaches include the direct anterior, direct lateral and posterior approaches. A number of technical intricacies allow safe and efficient femoral and acetabular reconstruction when using each approach. Hip dislocation, abductor insufficiency, fracture and nerve injury are complications of THA, although their relative risk varies by approach. Numerous clinical trials have sought to elicit differences in patient-reported outcomes, complication rates and return to function among the surgical approaches. This review outlines some of the technical pearls of performing a THA through either a direct anterior, direct lateral or posterior approach. A literature review outlines the impact of surgical approach on clinical outcomes and clinically relevant complication rates. PMID:25799249

Rates of medial and/or lateral gutter impingement after total ankle replacement are not insignificant. If impingement should occur, it typically arises an average of 17 months after total ankle replacement. Our patient underwent treatment for right ankle medial gutter bony impingement with arthroscopic debridement 5 years after her initial total ankle replacement. Standard anteromedial and anterolateral portals and a 30° 2.7-mm-diameter arthroscope were used. An aggressive soft-tissue and bony resection was performed using a combination of curettes, a 3.5-mm shaver, a 5.5-mm unsheathed burr, a drill, and a radiofrequency ablator. This case shows that arthroscopic treatment is an effective and potentially advantageous alternative to open treatment of impingement after total ankle replacement. In addition, symptoms of impingement often improve in a short amount of time after arthroscopic debridement of the medial and/or lateral gutter. PMID:27354942

Posterior internal impingement (PII) of the glenohumeral joint is a common cause of shoulder complex pain in the overhead athlete. This impingement is very different from standard outlet impingement seen in shoulder patients. Internal impingement is characterized by posterior shoulder pain when the athlete places the humerus in extreme external rotation and abduction as in the cocking phase of pitching or throwing. Impingement in this position occurs between the supraspinatus and or infraspinatus and the glenoid rim. Understanding regarding this pathology continues to evolve. Definitive understanding of precipitating factors, causes, presentation and methods of treatment have yet to be determined. A high index of suspicion should be used when attempting to make this diagnosis. This current concepts review presents the current thinking regarding pathophysiology, evaluation, and treatment of this condition. Level of Evidence: 5 PMID:23593557

Marine organisms comprised about 70% of the total impinged materials by weight at water intake screens in the Kapar Power Station (KPS), Malaysia. The general groupings of 'fish', 'shrimp', 'crab', 'cephalopod' and 'others' contributed 26% (87 species), 65% (29), 2% (17), 2% (3) and 5% (42) of the total number of impinged organisms, respectively. In general, higher impingement occurred during spring tide, at nighttime and in shallow water. The glass perchlet, anchovies, ponyfishes, mojarra, catfishes, hairtail, scat and young croakers were the most vulnerable fishes. Vulnerable invertebrates included cephalopods, sea urchin, rockshells and jellyfishes, but penaeid shrimps were the most susceptible in terms of both mortality and body injury. Annually, KPS is estimated to kill 8.5 x 10(6) marine organisms (42 tons) by impingement. This amount, however, is minimal compared to commercial fishery harvests. Multispecies impingement at Malaysian power plants poses the problem of finding the best mitigation options for tropical situations. PMID:20338631

A cooling arrangement (56) having: a duct (30) configured to receive hot gases (16) from a combustor; and a flow sleeve (50) surrounding the duct and defining a cooling plenum (52) there between, wherein the flow sleeve is configured to form impingement cooling jets (70) emanating from dimples (82) in the flow sleeve effective to predominately cool the duct in an impingement cooling zone (60), and wherein the flow sleeve defines a convection cooling zone (64) effective to cool the duct solely via a cross-flow (76), the cross-flow comprising cooling fluid (72) exhausting from the impingement cooling zone. In the impingement cooling zone an undimpled portion (84) of the flow sleeve tapers away from the duct as the undimpled portion nears the convection cooling zone. The flow sleeve is configured to effect a greater velocity of the cross-flow in the convection cooling zone than in the impingement cooling zone.

This article presents a case of a patient with degenerative hip disease in paralytic dislocation by poliomyelitis. Poliomyelitis is an acute infection disease caused by a group of neurotrophic viruses, which has a special affinity by the anterior horns cells of the spinal cord and for certain motor nuclei of the brain stem. Paralysis is a flaccid type and characteristically paralysis is asymmetrical. It is said that the joints of the affected limb by poliomyelitis are protected from the development of osteoarthritis. Hip dislocation in poliomyelitis is an acquired deformity caused by flaccid paralysis and the resulting muscular imbalance. In young children, when the gluteus maximus and medius muscles are paralyzed and the hip flexors and adductors are of normal strength, eventual luxation of the hip is almost inevitable. Hip osteoarthritis in a limb with poliomyelitis is an unusual entity because these limbs do not support excessive loads. In patients who present with the residual effects of poliomyelitis including degenerative disease and hip dysplastic, surgery is one of the most difficult challenges faced by reconstructive surgeons. In such cases, surgeons should attempt to optimize the component position and choice, surgical approach, and soft tissue tensioning because stability of the prosthesis can be problematic. PMID:19292189

EDUCATIONAL OBJECTIVES As a result of reading this article, physicians should be able to: 1. Describe the advantages of hip resurfacing. 2. Describe the disadvantages of hip resurfacing. 3. Identify the population in which hip resurfacing is most often indicated. 4. Demonstrate how to properly postoperatively manage patients with metal-on-metal prostheses. Hip resurfacing offers a suitable solution for young patients affected by hip disease who have high function demands and good bone quality. Bone stock preservation, restoration of the normal proximal femur anatomy, the lack of stress shielding, and the possibility of resuming sporting activity are proven advantages of hip resurfacing. However, there are some disadvantages, such as fracture of the femoral neck, onset of neck narrowing, and possible complications due to the metal-on-metal bearings, including pseudotumors, peri-implant osteolysis, and chronic elevation of metal ions in serum levels. Recent data suggest that the ideal candidate for hip resurfacing is an active male, younger than 65 years, with primary or posttraumatic osteoarthritis, and with a femoral head diameter larger than 50 to 54 mm. Based on these selection criteria, the literature reports implant survival to be similar to that of total hip arthroplasty. The current authors' experience confirms a low failure rate and excellent functional outcomes, with metal ion serum levels becoming stable over time in well-functioning implants. Proper surgical technique, correct patient selection, and the right choice of a well-established prosthetic model are essential elements for the long-term success of these implants. PMID:26270748

The process of impinging water droplets on Streptococcus mutans biofilms was studied experimentally and numerically. Droplets were experimentally produced by natural breakup of a cylindrical liquid jet. Droplet diameter and velocity were varied between 20 and 200 μm and between 20 and 100 m/s, respectively. The resulting erosion process of the biofilm was determined experimentally with high-speed recording techniques and a quantitative relationship between the removal rate, droplet size, and velocity was determined. The shear stress and the pressure on the surface during droplet impact were determined by numerical simulations, and a qualitative agreement between the experiment and the simulation was obtained. Furthermore, it was shown that the stresses on the surface are strongly reduced when a water film is present.

The statistical properties of tangential flows over surfaces were investigated by two techniques. In one, a laser-Doppler velocimeter was used in a smoke-laden jet to measure one-point statistical properties, including mean velocities, turbulent intensities, intermittencies, autocorrelations, and power spectral densities. In the other technique, free stream and surface pressure probes connected to 1/8 inch microphones were used to obtain single point rms and 1/3 octave pressures, as well as two point cross correlations, the latter being converted to auto spectra, amplitude ratios, phase lags, and coherences. The results of these studies support the vortex model of jets, give some insights into the effects of surface impingement, and confirm that jet diameter and velocity are the scaling parameters for circular jets, while Reynolds number is relatively unimportant.

The objective of the present work is to improve the accuracy of the k-epsilon turbulence model for flows involving one or more jets impinging on a plate in a crossflow which generate a horseshoe vortex. The k-epsilon model is modified by adding source terms to the epsilon equation, which enables it to more accurately predict the shear stress in flows subject to streamline curvature and vortex stretching (or lateral divergence). Calculations with the modified model predict the ground vortex core to be about 15 percent upstream of its experimental location. This is a significant improvement over the standard model which yields higher errors for calculation of the vortex-core location.

Tests were conducted in an acoustic wind tunnel to determine surface pressure spectra and far field noise caused by turbulence impinging on an airfoil and turbulence convected past a sharp trailing edge. Measured effects of flow velocity and turbulence intensity were compared with predictions from several theories. Also, tests were conducted in an anechoic chamber to determine surface pressure spectra and far field noise caused by a deflected airfoil scrubbed by a subsonic jet. This installation simulated both an under-the-wing and an upper-surface-blowing externally blown flap, depending on the deflection angle. Surface and far field spectra, and cross correlation coherence and delay time, were utilized to infer the major noise-producing mechanisms.

A theoretical model for entropy generation and utilization of work potential (exergy) in flame impingement (both premixed and diffusion) heat transfer has been developed in this article, to offer physical insights on the optimal operational regimes, depicting high values of the surface heat flux with minimal exergy destruction, within the practical constraints. The irreversibility components due to different physical processes have been evaluated from a general entropy transport equation. The velocity, temperature, and species concentration fields required for the solution of entropy transport equation have been determined from the numerical computation of flow-field in the flame. Global two-step chemical kinetics has been considered with methane (CH4) and air as fuel and oxidizer, respectively. The results have been predicted in terms of average nondimensional heat flux, expressed as Nusselt number at the target plate, the irreversibility components, and second law efficiency, as functions of the pertinent input parameters such as the jet Reynolds number and the ratio of plate separation distance to nozzle diameter (H /d). The average Nusselt number has been found to increase with an increase in jet Reynolds number and a decrease in H /d ratio, up to a value of 8. The dominant source of thermodynamic irreversibility in a premixed flame has been attributed to the thermal energy exchange whereas, in a diffusion flame, the same has been attributed to an uncontrolled exchange of electrons accompanying the reactive kinetics. The second law efficiency has been found to increase with an increase in jet Reynolds number and an increase in the H /d ratio, up to a value of 20. Values of the jet Reynolds number greater than 10 000 and H /d ratio in the tune of 15 have been observed to pertain to the regime of optimum flame impingement heat transfer, consistent with the energy and exergy balance constraints.

To confirm the therapeutic importance of hip arthroplasty in athletes whose pain precludes sportive function of the hip joint, being able to minimize it to the extent of helping on the return of sports practice at satisfactory levels. Methods: 49 athlete patients (51 hips) submitted to hip arthroscopy complaining of pain and inability to practice sports were assessed. Follow-up time ranged from 12 to 74 months (mean: 39.0 months). Preoperatively, pain site, severity according to Facial Expression Scale (FES) and the degree of disability using the modified Harris Hip Score (HHS) were assessed. Different diagnoses were provided, which led to the indication of arthroscopy, such as femoralacetabular impact, acetabular lip injury not secondary to femoral-acetabular impact, etc. Postoperatively, the patients were assessed by using the same methods as used at baseline and by the subjective analysis of return to sports activities. Results: Based on pre-and postoperative HHS and FES, the statistical analysis showed significance between values. We found some improvement in all cases and return to sports activities at a satisfactory level in most of the cases. Conclusion: As a result of our study, we confirm that arthroscopy in athletes with local hip injuries is an effective technique, able to promote the return to sports practice in most of the cases, without pain, and with an effective joint function, provided well indicated. PMID:26998449

Summary Background: sports hernia is a well-recognized cause of groin pain in athletes involved in sports, especially football and rugby. Loss of range of motion of the hip joint is a possible contributory factor to stress across the symphysis pubis leading to the instability. Methods: twenty-five athletes presenting with sports hernia were matched to age, sex, physical/sports activity and co-morbidities with twenty-five athletes without sports hernia. The range of movement of both the hips was compared in athletes of both the groups. Results: there was marked restriction of internal rotation with the hip flexed to 90 degrees (average 17 degrees) and external rotation (average 26 degrees) in sports hernia group compared to the control group. Other movements of the hip were comparable in both the groups. Conclusion: the study highlights observation of limitation of hip rotation with the hip flexed to 90 degrees as a possible factor in the aetiology of sports hernia. There may be an association with other pathologies of the hip such as impingement that requires further investigation. Though this study has its limitation in being a small number and a case control study, it does helps in understanding the possible mechanism of development of this condition. PMID:25878984

In Japan, osteoarthritis (OA) of the hip secondary to acetabular dysplasia is very common, and there are few data concerning the pathogeneses and incidence of femoroacetabular impingement (FAI). We have attempted to clarify the radiological prevalence of painful FAI in a cohort of Japanese patients and to investigate the radiological findings. We identified 176 symptomatic patients (202 hips) with Tönnis grade 0 or 1 osteoarthritis, whom we prospectively studied between August 2011 and July 2012. There were 61 men (65 hips) and 115 women (137 hips) with a mean age of 51.8 years (11 to 83). Radiological analyses included the α-angle, centre-edge angle, cross-over sign, pistol grip deformity and femoral head neck ratio. Of the 202 hips, 79 (39.1%) had acetabular dysplasia, while 80 hips (39.6%) had no known aetiology. We found evidence of FAI in 60 hips (29.7%). Radiological FAI findings associated with cam deformity were the most common. There was a significant relationship between the pistol grip deformity and both the α-angle (p < 0.001) and femoral head-neck ratio (p = 0.024). Radiological evidence of symptomatic FAI was not uncommon in these Japanese patients. PMID:24493180

An impingement insert sleeve is provided that is adapted to be disposed in a coolant cavity defined through a stator vane. The insert has a generally open inlet end and first and second pairs of diametrically opposed side walls, and at least one fail-safe tab defined at a longitudinal end of the insert for limiting radial displacement of the insert with respect to the stator vane.

The incidence of traumatic hip dislocations in children is rising in this fast developing world along with increasing numbers of high-velocity road traffic accidents. Anterior dislocation of the hip has a lower incidence compared with posterior dislocation of the hip. We encountered a rare case of the obturator type of anteriorly dislocated hip associated with ipsilateral fracture of the shaft femur in an 11-year-old child. This is a highly unusual injury combination and the mechanism of injury is obscure. Only two similar cases have been reported in the English literature to date. Closed reduction of the hip using a hitherto undescribed technique and an intramedullary interlocking nail was performed in this case. At 6 months of follow-up, the fracture shaft femur has united and the child is bearing full weight on the limb. PMID:27128394

Background It is often challenging to find the causes for postoperative pain syndromes after total hip replacement, since they can be very allotropic. One possible cause is the muscular impingement syndrome. The most commonly known impingement syndrome is the psoas impingement. Another recently described impingement syndrome is the obturator externus muscle impingement. The aim of this study is to analyze pathological conditions of the Obturator externus and to show possible causes. Methods 40 patients who had undergone a total hip replacement were subjected to clinical and MRI examinations 12 months after the surgery. The Harris Hip Score (HHS) was used to analyze pain and function. Additionally, a satisfaction score and a pain score (VAS) were determined. The MRI allowed for the assessment of the spatial relation between the obturator externus muscle and the acetabulum. Also measured were the acetabular inclination angle as well as the volume and cross-sectional area of the obturator externus muscle. Results The patients were assigned to 3 groups in accordance with their MRI results. Group 1 patients (n = 18) showed no contact between the obturator externus and the acetabulum. Group 2 (n = 13) showed contact, and group 3 (n = 9) an additional clear displacement of the muscle in its course. It was not possible to establish a connection between the imaging findings, the HHS, the VAS, and patient satisfaction. What was striking, however, was a significant difference between the median inclination angle in group 1 (40° ± 5.4°) and group 3 (49° ± 4.7°) (p < 0.05), and the corresponding image-morphological pathology. The average inclination angle in group 2 was 43.3° ± 3.8° Conclusion Contact between the obturator externus muscle and the caudal acetabula border occurs frequently, but is only rarely accompanied by a painful muscular impingement. The position of the acetabula must be seen as one of the main risk factors for contact between the acetabula border

An experiment was performed to assess CFD modeling of a hypersonic-vehicle breach, boundary-layer flow ingestion and internal surface impingement. Tests were conducted in the NASA Langley Research Center 31-Inch Mach 10 Tunnel. Four simulated breaches were tested and impingement heat flux data was obtained for each case using both phosphor thermography and thin film gages on targets placed inside the model. A separate target was used to measure the surface pressure distribution. The measured jet impingement width and peak location are in good agreement with CFD analysis.

In bipedal runners and hoppers the hip is not located at the center of mass in the sagittal projection. This displacement influences operation and energetics of the leg attached to the hip. To investigate this influence in a first step a simple conservative bouncing template is developed in which a heavy trunk is suspended to a massless spring at a pivot point above the center of mass. This model describes the orientation of the ground reaction forces observed in experiments on running birds. In a second step it is assumed that an effective telescope leg with its hip fixed to the trunk remote from the COM generates the same ground reaction forces as those predicted by the template. For this effective leg the influence of hip placement on leg operation and energetics is investigated. Placing the hip directly below, at, or above the pivot point results in high axial energy storage. Posterior placement increases axial losses and hip work whereas anterior placement would require axial work and absorption at the hip. Shifting the hip far posteriorly as observed in some birds can lead to the production of pure extension torques throughout the stance phase. It is proposed that the relative placement of the hip with respect to the center of mass is an important measure to modify effective leg operation with possible implications for balancing the trunk and the control of legged motion systems. PMID:26142948

Persistent pain following hip arthroplasty remains a concern, especially in young, active patients. Four hundred twenty patients less than 60 years of age with a pre-symptomatic UCLA score ≥ 6 (196 total hip arthroplasty [THA]; 224 surface replacement arthroplasty [SRA]) completed a pain-drawing questionnaire investigating the location, severity, and frequency of pain around the hip. At a mean of 2.9 years of follow-up, 40% reported pain in at least one location around the hip. There was no difference in the incidence of groin pain between SRA and THA patients (32% vs. 29%, P=0.6), but THA patients had a greater incidence of anterior (25% vs. 8%, P<0.001) and lateral (20% vs. 10%, P=0.01) thigh pain. A high percentage of young, active patients experience persistent pain following hip arthroplasty. PMID:26067707

Anterior cervical hypertrichosis was described by Trattner and coworkers in 1991. It consists of a of hair at the anterior cervical level just above the laryngeal prominence. To date, only 28 cases of anterior cervical hypertrichosis have been reported. Although it is normally an isolated finding, it may be associated with mental retardation, hallux valgus, retinal disorders, other hair disorders, facial dysmorphism, or sensory and motor peripheral neuropathy. We report the case of a 27-year-old woman who presented with this condition as an isolated finding. PMID:19268113

... hip socket. The socket is usually made of metal. A liner that fits inside the socket. It ... usually plastic, but some surgeons use ceramic and metal. The liner allows the hip to move smoothly. ...

Advantages posed by self-cleaning, superhydrophobic surfaces quickly diminish as the liquid penetrates gas-filled cavities resulting in the so-called Wenzel state. To prevent penetration, surfaces must exhibit nanoscale features since penetrating pressure increases significantly for decreasing feature size. However, certain applications require microscale roughness such as those seeking to relax the no-slip condition and thus penetration reversal in microscale features remains of interest. Unfortunately, recent efforts to accomplish such reversal are complicated or locally-disruptive to the flow such as electrically-tunable surfaces and boiling. Here, we show that a Wenzel-to-Cassie transition is possible with a modest surface temperature increase. Dynamics are discussed for a water droplet impinging (We =100) on a wide range of superhydrophobic surfaces with features varying in height from 4 microns to 18 microns and separation distance of 8 microns to 16 microns. Results reveal that dewetting rates increase with increasing feature height and temperature up to 30 mL/s. A first order model is constructed to validate our hypothesis that surface tension and triple line dissipation are the two dominating forces during dewetting. Good agreement is found between the model and experimental results. We gratefully acknowlege the National Science Foundation for funding this work.

The configuration of total hip arthroplasty (THA) implants has constantly evolved since they were first introduced. One of the key components of THA design is the diameter of the prosthetic femoral head. It has been well established that the risk of dislocation is lower as the head diameter increases. But head diameter impacts other variables beyond joint stability: wear, cam-type impingement, range of motion, restoration of biomechanics, proprioception and groin pain. The introduction of highly cross-linked polyethylene and hard-on-hard bearings has allowed surgeons to implant large-diameter heads that almost completely eliminate the risk of dislocation. But as a result, cup liners have become thinner. With femoral head diameters up to 36 mm, the improvement in joint range of motion, delay in cam-type impingement and reduction in dislocation risk have been clearly demonstrated. Conversely, large-diameter heads do not provide any additional improvements. If an "ecologically sound" approach to hip replacement is embraced (e.g. keeping the native femoral head diameter), hip resurfacing with a metal-on-metal bearing must be carried out. The reliability of large-diameter femoral heads in the longer term is questionable. Large-diameter ceramic-on-ceramic bearings may be plagued by the same problems as metal-on-metal bearings: groin pain, squeaking, increased stiffness, irregular lubrication, acetabular loosening and notable friction at the Morse taper. These possibilities require us to be extra careful when using femoral heads with a diameter greater than 36 mm. PMID:25596984

Conditions that occur in the dancer's hip fall into the following categories: poor training; conditions that occur as the result of normal use; overuse syndromes, including tendinitis and myositis; and conditions referring pain to the hip. Dancers are highly motivated and goal oriented and often suppress symptoms for long periods, making diagnosis and treatment difficult. Observing the dancer at work and understanding his art are emphasized, and a practical guide to therapy is presented. Development of proper dance technique and a proper flexibility program can decrease the incidence of injuries. PMID:6652698

Surgical complications of hip arthroscopies are rare in the hands of experienced hip arthroscopists. However, when performed by beginners and in more demanding situations such as marginal distraction of the head and socket and technically advanced procedures, the risk increases. This report describes possible complications which may happen during positioning and traction, portal placement, and diagnostic and therapeutic procedures. Possible causes of soft tissue lesions of the portal area, perineum and foot, intra-articular lesions of the labrum and cartilage, direct and traction-related indirect neurovascular lesions, and other rare complications are analyzed. PMID:18854972

In many liquid metal MHD power, cycles, it is necessary to separate the phases of a high-speed liquid-gas flow. The usual method is to impinge the jet at a glancing angle against a solid surface. These surface separators achieve good separation of the two phases at a cost of a large velocity loss due to friction at the separator surface. This report deals with attempts to greatly reduce the friction loss by impinging two jets against each other. In the crude impinging jet separators tested to date, friction losses were greatly reduced, but the separation of the two phases was found to be much poorer than that achievable with surface separators. Analyses are presented which show many lines of attack (mainly changes in separator geometry) which should yield much better separation for impinging jet separators).

Overuse and acute injuries to the upper body are common in rock climbing. Such injuries primarily affect the fingers; but shoulder problems are increasingly common, especially among more experienced and older climbers who climb at a high ability level. Such shoulder problems are often due to subacromial impingement, shoulder dislocations with bankart lesions, hyperlaxity, SLAP lesions or irritations of the long biceps tendon. In contrast to these known conditions, we describe a case of an ambitious female rock climber who trained intensively and developed a coracoid impingement caused by hypertrophied subscapularis tendon and muscle following sport-specific training. Diagnosis was made through clinical evaluation and confirmed by magnetic resonance tomography. Coracoid impingement syndrome is a less common cause of shoulder pain and occurs when the subscapularis tendon impinges between the coracoid and the lesser tuberosity of the humerus. The patient was treated successfully with a conservative therapy and returned to full activity within 6 weeks. PMID:21429776

Symptomatic subfibular and/or lateral talocalcaneal impingement in pediatric patients may result from an accessory anterolateral talar facet (AALTF). This impingement may cause pain and disability and may limit athletic performance in high-level athletes. We report the case of a 12-year-old female competitive gymnast who had refractory, lateral-sided right ankle pain for 4 months and underwent right ankle arthroscopic resection of the AALTF causing impingement. Standard medial and anterolateral portals with the addition of an accessory anterolateral-distal portal were used in conjunction with a 30° 2.7-mm-diameter arthroscope. The AALTF was resected with a combination of a shaver and a motorized rasp. Intraoperative fluoroscopy was used to verify successful debridement of the bony facet. This case illustrates that arthroscopic debridement is a technique to treat subfibular and/or talocalcaneal impingement associated with an AALTF. PMID:27462543

A painful shoulder presents challenges in examination, diagnosis and intervention for the physical therapist because of the complexity of the structures involved. A common cause of shoulder pain is shoulder impingement syndrome. This was first described as a condition in which the soft tissues of the subacromial space were chronically entrapped and compressed between the humeral head and the subacromial arch. This definition does not account for the myriad potential causes of shoulder impingement conditions, as forms of impingement other than subacromial soft tissue compression may explain different symptomatic shoulder injuries. This paper describes shoulder impingement syndromes that have been hypothesized, identified and analyzed in the literature. Physical Therapy examination and intervention for these syndromes are also discussed. PMID:25792938

The impact of power plant impingement on the 1974 and 1975 year classes of the Hudson River white perch population is assessed using a simple model derived from Ricker's theory of fisheries dynamics. The impact of impingement is expressed in the model as the conditional mortality rate, rather than as the more commonly used exploitation rate. Since the calculated impact is sensitive to errors in the estimation of population size and total mortality, ranges of probable values of these quantities are used to compute upper and lower bounds on the fractional reduction in abundance of each year class. Best estimates of abundance and mortality are used to compute the conditional impingement mortality rate separately for each plant and month. The results are used to assess the relative impacts of white perch impingement at six Hudson River power plants and to identify the seasons during which the impact is highest.

Clinical examination techniques need to allow the physician to determine the underlying pathology of a patient’s condition with confidence. This review examines the evidence for two common conditions: impingement and rotator cuff disease

A system for cooling a wall (24) of a component having an outer surface with raised ribs (12) defining a structural pocket (10), including: an inner wall (26) within the structural pocket and separating the wall outer surface within the pocket into a first region (28) outside of the inner wall and a second region (40) enclosed by the inner wall; a plate (14) disposed atop the raised ribs and enclosing the structural pocket, the plate having a plate impingement hole (16) to direct cooling air onto an impingement cooled area (38) of the first region; a cap having a skirt (50) in contact with the inner wall, the cap having a cap impingement hole (20) configured to direct the cooling air onto an impingement cooled area (44) of the second region, and; a film cooling hole (22) formed through the wall in the second region.

Two-dimensional arrays of circular air jets impinging on a heat transfer surface parallel to the jet orifice plate are considered. The jet flow, after impingement, is constrained to exit in a single direction along the channel formed by the jet orifice plate and the heat transfer surface. In addition to the crossflow which originates from the jets following impingement, an initial crossflow is present which approaches the array through an upstream extension of the channel. The temperature of the initial crossflow air may differ from the jet air temperature. The configurations considered are intended to model the impingement cooled midchord region of gas turbine airfoils in cases where an initial crossflow is also present. Nusselt numbers and dimensionless adiabatic wall temperatures resolved to one streamwise jet hole spacing were experimentally determined for ratios of the initial crossflow rate to the total jet flow rate ranging from zero to unity. These are presented and discussed relative to the flow and geometric parameters.

This paper describes an experimental method to visualize the impingement process of a liquid droplet onto a solid surface with sufficient clarity to reveal fine details of the droplet surface structure and rim jet produced during the impingement process. The method incorporates a 35 mm SLR camera with bellows, motor drive, macro lens, backlighting by a short duration flash lamp, diffusers and a commercially available timing control unit to trigger the flash. Results using the experimental arrangement are demonstrated for a water droplet striking a horizontal surface at a velocity of about 1 m/s, though the photographic method may be applied to any other condition and liquid. A series of photographs are presented that show the repeatability of the impingement process, image clarity, surface structure of the droplet during impingement.

Curved periacetabular osteotomy (CPO) was developed for the treatment of dysplastic hips in 1995. In CPO, the exposure of osteotomy sites and osteotomy of the ischium are made in the same manner as Bernese periacetabular osteotomy, and iliac and pubic osteotomies are performed in the same manner as rotational acetabular osteotomy. We studied the dynamic instabilities of 25 dysplastic hips before and after CPO using triaxial accelerometry. Overall magnitude of acceleration was significantly decreased from 2.30 ± 0.57 m/sec(2) preoperatively to 1.55 ± 0.31 m/sec(2) postoperatively. Pain relief and improvement of acetabular coverage resulting from acetabular reorientation seem to be related with reduction of dynamic instabilities of dysplastic hips. Isokinetic muscle strengths of 24 hips in 22 patients were measured preoperatively and after CPO. At 12 months postoperatively, the mean muscle strength exceeded the preoperative values. These results seem to be obtained due to no dissection of abductor muscles in CPO. The preoperative presence of acetabular cysts did not influence the results of CPO. An adequate rotation of the acetabular fragment induced cyst remodeling. Satisfactory results were obtained clinically and radiographically after CPO in patients aged 50 years or older. CPO alone for the treatment of severe dysplastic hips classified as subluxated hips of Severin group IV-b with preoperative CE angles of up to -20° could restore the acetabular coverage, weight-bearing area and medialization of the hip joint. CPO without any other combined procedure, as a treatment for 17 hips in 16 patients with Perthes-like deformities, produced good mid-term clinical and radiographic results. We have been performing CPO in conjunction with osteochondroplasty for the treatment of acatabular dysplasia associated with femoroacetabular impingement since 2006. The combined procedure has been providing effective correction of both acetabular dysplasia and associated femoral

The impingement of supersonic jets on surfaces is of interest because of its important application to jet blast deflectors (JBD), and short takeoff and vertical landing aircraft (STOVL) during hover. Typically, on an aircraft carrier deck, the impingement of the jet blast on the deflector generates impingement tones, and structural vibrations, not only on the JBD but also on the ship deck. Therefore, apart from direct transmission of jet noise to the gallery level, there is a component of noise transmitted due to the impingement of the jet on the JBD. The objectives of this work are to study the pressure spectra (i) on a flat plate, and separately on a cone due to axisymmetric impingement of a supersonic underexpanded cold jet issuing from a convergent-divergent nozzle and (ii) on a plane jet impinging on a finite plate and an adjoining ground plane due to the impingement of a planar jet on the plate. The characteristics of the surface pressure fluctuations are numerically investigated using WIND-US 2.0. The time-dependent, compressible Euler equations for perfect gas are employed for the present computations. The impingement distance between the jet nozzle and the deflector plate, and the plate inclination with respect to the incident jet are varied. The impingement zone stagnation bubble and a high-speed radial jet with several embedded structures (shocklets) were identified on the perpendicular plate. Flows involving cones reveal the presence of detached cone shocks, enclosing a recirculation zone. The location and magnitude of the peak pressure on the cone surface are a strong function of the cone apex angle. For the two-dimensional jet impingement on angled plate the peak value of pressure occurs at normal jet impingement. The pressure at the intersection point of the plate and the ground plane is sometimes higher than the peak pressure on the plate. Beyond this point there is a sharp decrease in pressure. As the flow accelerates, an oblique shock is sometimes

We describe and analyze the flow dynamics in replicas of a human anterior communicating artery aneurysm. The replicas were placed in a circuit of pulsating non-Newtonian fluid, and flows were adjusted to replicate human physiologic parameters. Individual slipstreams were opacified with isobaric dyes, and images were recorded on film and by CT/MR angiography. When flow in the afferent (internal carotid) and efferent (anterior and middle cerebral) arteries was bilaterally equal, slipstreams rarely entered the aneurysm. When flow in either the afferent or efferent vessels was not symmetrical, however, slipstreams entered the aneurysm neck, impinged upon the aneurysm dome, and swirled within the aneurysm. Unequal flow in carotid or cerebral systems may be necessary to direct pathologic, fluid slipstreams into an aneurysm. PMID:10588134

Plume impingement analyses were performed for the European Service Module (ESM) propulsion system Orbital Maneuvering System engine (OMS-E), auxiliary engines, and reaction control system (RCS) engines. The heat flux from plume impingement on the solar arrays and other surfaces are evaluated. This information is used to provide inputs for the ESM thermal analyses and help determine the optimal configuration for the RCS engines.

The interaction of various factors in the vicious cycle (VC) of subacromial impingement syndrome (SIS) is complex and there are conservative treatment preferences for speedy rehabilitation. The mechanism of SIS is not fully understood and the inappropriate treatment priorities cause delay in rehabilitation. SIS is related to the reduction in the subacromial space (SS). Posterior capsular tightness (PCT) and rotator cuff (RC) dysfunction are the two basic mechanisms in this regard. PCT may cause anterosuperior translation of humeral head (HH) and anterior acromion tipping through scapular dyskinesis, thereby reducing the subacromial space. Alteration in the force couple of muscle secondary to scapular dyskinesis eventually causes injury to subacromial structures. The rotator cuff is important in centring the humeral head in the glenoid cavity and superior translation of humeral head occurs if their function is compromised. Posterior capsular tightness may affect the function of rotator cuff action which leads to early fatigue, dysfunction of these muscles and eventually impingement. Adhesive changes take place in various structures around the shoulder secondary to impingement pain and relative immobility, which further aggravates the problem. To reverse the vicious cycle, conservative intervention should therefore be directed to loosen posterior capsular tightness, restore rotator cuff function through appropriate exercise in a pain-free range through appropriate exercise, mobilisation of adhesion through teraservers friction or pain-free mobilisation or grade I and grade II manipulation. Depending on the level of irritability, pain control intervention could be considered alongside. PMID:26028390

Synovial osteochondromatosis is a benign metaplasia of the synovium resulting in the formation of osteocartilaginous nodules within the synovial lining. At presentation, radiographs typically reveal these nodules to have broken free from the synovial lining, becoming loose bodies residing in the free space of the affected joint. These fragments readily receive the necessary nutrients for continued growth from the synovial fluid in which they reside. Controversy exists over the management of the disease. Some physicians call for arthrotomy with a complete synovectomy, whereas others vouch for a minimally invasive arthroscopic approach. In the case described here, the surgeon decided on hip arthroscopy to treat synovial osteochondromatosis in a 61-year-old woman. All but one loose body that was adherent in the anteriorhip capsule was successfully removed and the patient recovered promptly. This case highlights the importance of hip arthroscopy and its usefulness not only in treating conditions such as synovial osteochondromatosis, but also in accurately diagnosing them. Recognition and management of hip conditions such as synovial osteochondromatosis through arthroscopy result in minimally invasive treatment and decreased morbidity and may markedly accelerate patient rehabilitation. It is the authors' belief that this unique case further suggests the practicality of using hip arthroscopy to successfully treat synovial osteochondromatosis. PMID:26091229

Human sensorimotor control involves inter-segmental coordination to cope with the complexity of a multi-segment system. The combined activation of hip and ankle muscles during upright stance represents the hip-ankle coordination. This study postulates that the coordination emerges from interactions on the sensory levels in the feedback control. The hypothesis was tested in a model-based approach that compared human experimental data with model simulations. Seven subjects were standing with eyes closed on an anterior-posterior tilting motion platform. Postural responses in terms of angular excursions of trunk and legs with respect to vertical were measured and characterized using spectral analysis. The presented control model consists of separate feedback modules for the hip and ankle joints, which exchange sensory information with each other. The feedback modules utilize sensor-derived disturbance estimates rather than 'raw' sensory signals. The comparison of the human data with the simulation data revealed close correspondence, suggesting that the model captures important aspects of the human sensory feedback control. For verification, the model was re-embodied in a humanoid robot that was tested in the human laboratory. The findings show that the hip-ankle coordination can be explained by interactions between the feedback control modules of the hip and ankle joints. PMID:25150802

The acetabular labrum is believed to have a sealing function. However, a torn labrum may not effectively prevent joint fluid from escaping a compressed joint, resulting in impaired lubrication. We aimed to understand the role of the acetabular labrum in maintaining a low friction environment in the hip joint. We did this by measuring the resistance to rotation (RTR) of the hip, which reflects the friction of the articular cartilage surface, following focal and complete labrectomy. Five cadaveric hips without evidence of osteoarthritis and impingement were tested. We measured resistance to rotation of the hip joint during 0.5, 1, 2, and 3 times body weight (BW) cyclic loading in the intact hip, and after focal and complete labrectomy. Resistance to rotation, which reflects articular cartilage friction in an intact hip was significantly increased following focal labrectomy at 1-3 BW loading, and following complete labrectomy at all load levels. The acetabular labrum appears to maintain a low friction environment, possibly by sealing the joint from fluid exudation. Even focal labrectomy may result in increased joint friction, a condition that may be detrimental to articular cartilage and lead to osteoarthritis. PMID:22176711

The metal-on-metal articulations in total hip arthroplasty (THA) were widely used between 1960 and 1975. The McKee-Farrar and other first-generation prostheses failed at a high rate because impingement caused early component loosening. The problem of early component loosening was corrected by improved component design and better manufacturing quality. Second-generation metal-on-metal total hip replacements have experienced short and medium-term success as assessed by Harris Hip Scores and patient selfassessment. The combined annual linear wear of the metal-on-metal femoral head and acetabular insert is less than 10 mm and osteolysis has only rarely been observed in association with well-fixed metal-on-metal total hip replacements. Hypersensitivity is not a common cause of loosening with second-generation hip replacements and remains to be proven as a definitive diagnosis in unusual cases of unexplained pain. More than 40 years of use has demonstrated no increase in the incidence of renal failure or cancer in patients with metal-on-metal total hip replacements. The scientific evidence of the results using the metal-on-metal articulations would recommend its continued use in any patient who does not have compromised renal function. PMID:16089065

A capital drop is a type of osteophyte at the inferomedial portion of the femoral head commonly observed in hip osteoarthritis (OA), secondary to developmental dysplasia. Capital drop itself is typically asymptomatic; however, symptoms can appear secondary to impinge against the acetabulum or to irritation of the surrounding tissues, such as nerves, vessels, and tendons. We present here a case of unilateral leg edema in a patient with hip OA, caused by a huge bone mass occurring at the inferomedial portion of the femoral head that compressed the femoral vessels. We diagnosed this bone mass as a capital drop secondary to hip OA after confirming that the mass occurred at least after the age of 63 years based on a previous X-ray. We performed early resection and total hip arthroplasty since the patient's hip pain was due to both advanced hip OA and compression of the femoral vessels; moreover, we aimed to prevent venous thrombosis secondary to vascular compression considering the advanced age and the potent risk of thrombosis in the patient. A large capital drop should be considered as a cause of vascular compression in cases of unilateral leg edema in OA patients. PMID:26504606

Our understanding of the origin of hip pain in degenerative disorders of the hip, including primary osteoarthritis, avascular necrosis and femoroacetabular impingement (FAI), is limited. We undertook a histological investigation of the nociceptive innervation of the acetabular labrum, ligamentum teres and capsule of the hip, in order to prove pain- and proprioceptive-associated marker expression. These structures were isolated from 57 patients who had undergone elective hip surgery (44 labral samples, 33 ligamentum teres specimens, 34 capsular samples; in 19 patients all three structures were harvested). A total of 15,000 histological sections were prepared that were investigated immunohistochemically for the presence of protein S-100, 68 kDa neurofilament, neuropeptide Y, nociceptin and substance P. The tissues were evaluated in six representative areas. Within the labrum, pain-associated free nerve ending expression was located predominantly at its base, decreasing in the periphery. In contrast, the distribution within the ligamentum teres showed a high local concentration in the centre. The hip capsule had an almost homogeneous marker expression in all investigated areas. This study showed characteristic distribution profiles of nociceptive and pain-related nerve fibres, which may help in understanding the origin of hip pain. PMID:23723270

Over the last three centuries, treatment of hip arthritides has evolved from rudimentary surgery to modern total hip arthroplasty (THA), which is considered one of the most successful surgical interventions ever developed. We here review the history of the early hip arthroplasty procedures for hip arthritis that preceded Charley total hip arthroplasty. An evaluation of such past enterprises is relevant, and reminds us of the ephemeral nature of human industriousness, and how medical research and procedures are not isolated developments, but correlate to the social, economical, and cultural framework of their time. PMID:16089067

Sports related injuries to the hip have received relatively little attention, in the part because the clinical assessment, imaging studies, and surgical techniques are less sophisticated. The evolution of hip arthroscopy has offered a less invasive technique that allows for recognition and treatment of hip pathologies that previously went unrecognized. The success of hip arthoscopy is dependent on proper patient selection based on the patient's history and diagnosis. The purpose of this clinical commentary is to outline mechanisms of injury and specific lesions that can be addresses using hip arthoscopy. PMID:21509141

Hip arthroscopy is a fast-growing and evolving field. Like knee and shoulder arthroscopy, hip arthroscopy began as a diagnostic procedure and then progressed to biopsy and resection of abnormalities. Subsequently, it has evolved to repair of various tissues and treatment of underlying causes. As the understanding of the hip joint and its associated pathophysiology grows, indications will continue to expand for this diagnostic and therapeutic modality. This article outlines the historic developments of hip arthroscopy, including advancements in instrumentation and techniques from the days of the first hip arthroscopies to the present day. PMID:27343387

This document outlines the process used to bond monolithic fuel plates by Hot Isostatic Pressing (HIP). This method was developed at Idaho National Laboratory (INL) for the Reduced Enrichment for Research and Test Reactors (RERTR) program. These foils have been used in a number of irradiation experiments in support of the United States Global Threat Reduction Initiative (GTRI) program.

... by a blow, fall, or other trauma, a dislocation can also occur from birth. The cause is unknown but genetic factors may play a role. Problems resulting from very mild developmental dysplasia of the hip may not become apparent until the person is ...

Objectives: To determine the prevalence of complications in a series of consecutive cases of hip arthroscopy; to assess the progression of the sample through a learning curve; and to recognize the causes of complications in arthroscopic hip operations. Method: 150 consecutive cases that underwent hip arthroscopy between May 2004 and December 2008 were evaluated. The complications encountered were classified in three ways: organic system affected, severity and groups of 50 consecutive cases. The data were analyzed by means of descriptive statistics and Fisher's exact test. Results: We observed 15 complications in this study (10%): ten were neurological, two were osteoarticular, one was vascular-ischemic and two were cutaneous. In the classification of severity, three were classified as major, 12 as intermediate and none as minor. The incidence of complications over the course of the learning curve did not present any statistically significant difference (p = 0.16). Conclusions: Hip arthroscopy is a surgical procedure that involves low morbidity, but which presents complications in some cases. These complications are frequently neurological and transitory, and mainly occur because of joint traction. The complication rate did not decrease with progression of our sample. PMID:27022521

Assembly of the Space Station requires numerous construction flights by the Space Shuttle. A particularly challenging problem is that of control of each intermediate station configuration when the shuttle orbiter is approaching it to deliver the next component. The necessary braking maneuvers cause orbiter thruster plumes to impinge on the station, especially its solar arrays. This in turn causes both overall attitude errors and excitation of flexible-body vibration modes. These plume loads are predicted to lead to CMG saturation during the approach of the orbiter to the SC-5 station configuration, necessitating the use of the station RCS jets for desaturation. They are also expected to lead to significant excitation of solar array vibrations. It is therefore of great practical importance to investigate the effects of plume loads on the flexible dynamics of station configuration SC-5 as accurately as possible. However, this system possesses a great many flexible modes (89 below 5 rad/s), making analysis time-consuming and complicated. Model reduction techniques can be used to overcome this problem, reducing the system model to one which retains only the significant dynamics, i.e. those which are strongly excited by the control inputs or plume disturbance forces and which strongly couple with the measured outputs. The particular technique to be used in this study is the subsystem balancing approach which was previously developed by the present investigator. This method is very efficient computationally. Furthermore, it gives accurate results even for the difficult case where the structure has many closed-spaced natural frequencies, when standard modal truncation can give misleading results. Station configuration SC-5 is a good example of such a structure.

Assembly of the Space Station requires numerous construction flights by the Space Shuttle. A particularly challenging problem is that of control of each intermediate station configuration when the shuttle orbiter is approaching it to deliver the next component. The necessary braking maneuvers cause orbiter thruster plumes to impinge on the station, especially its solar arrays. This in turn causes both overall attitude errors and excitation of flexible-body vibration modes. These plume loads are predicted to lead to CMG saturation during the approach of the orbiter to the SC-5 station configuration, necessitating the use of the station RCS jets for desaturation. They are also expected to lead to significant excitation of solar array vibrations. It is therefore of great practical importance to investigate the effects of plume loads on the flexible dynamics of station configuration SC-5 as accurately as possible. However, this system possesses a great many flexible modes (89 below 5 rad/s), making analysis time-consuming and complicated. Model reduction techniques can be used to overcome this problem, reducing the system model to one which retains only the significant dynamics, i.e. those which are strongly excited by the control inputs or plume disturbance forces and which strongly couple with the measured outputs. The particular technique to be used in this study is the subsystem balancing approach which was previously developed by the present investigator. This method is very efficient computationally. Furthermore, it gives accurate results even for the difficult case where the structure has many closed-spaced natural frequencies, when standard modal truncation can give misleading results. Station configuration SC-5 is a good example of such a structure.

Various nozzle geometries for impingement cooling jets have recently been devised and favorable designs for cooling effectiveness have been reported. However, impinging flow and the characteristics of impingement cooling are not sufficiently clear. This paper reports on an investigation of impingement jet cooling techniques. The impingement cooling characteristics by oblique jets through a rectangular nozzle have been clarified. Preliminary numerical simulations have not necessarily presented the details of heat transfer characteristics of the oblique jets. PMID:12496016

An increasing number of children are taking up sporting activities and at more competitive levels. For this reason (pediatric) radiologists should expect to receive greater numbers of requests from their orthopedic colleagues to image the athletic child who presents with hip or groin pain: "athletic pubalgia."Lower limb sports-related pathology is particularly common in sports such as ballet, football, hockey, rugby, and running. Injuries to the hip and groin may account for up to a quarter of injuries seen in athletic children and may be acute or chronic, osseous, cartilaginous, ligamentous, or muscular. The radiologist should also bear in mind the possibility of non-sports-related pathology such as inflammation or tumor and of complications related to previous trauma such as avascular necrosis or femoroacetabular impingement complicating previous slipped capital femoral epiphysis. Radiologists should avoid use of the term sports hernia and provide a more specific description of the true abnormality.The major imaging modalities are radiographs and MRI. In this article we provide an overview of the common sports-related pathologies of the hip and groin that may be encountered in the athletic child. PMID:25350826

We developed an object-oriented cross-platform program to perform three-dimensional (3D) analysis of hip joint morphology using two-dimensional (2D) anteroposterior (AP) pelvic radiographs. Landmarks extracted from 2D AP pelvic radiographs and optionally an additional lateral pelvic X-ray were combined with a cone beam projection model to reconstruct 3D hip joints. Since individual pelvic orientation can vary considerably, a method for standardizing pelvic orientation was implemented to determine the absolute tilt/rotation. The evaluation of anatomically morphologic differences was achieved by reconstructing the projected acetabular rim and the measured hip parameters as if obtained in a standardized neutral orientation. The program had been successfully used to interactively objectify acetabular version in hips with femoro-acetabular impingement or developmental dysplasia. Hip(2)Norm is written in object-oriented programming language C++ using cross-platform software Qt (TrollTech, Oslo, Norway) for graphical user interface (GUI) and is transportable to any platform. PMID:17499878

Avulsion fracture of the anterior tibial eminence is an uncommon injury. If bone union does not occur, knee extension will be limited by impingement of the avulsed fragment and knee instability will be induced by dysfunction of the anterior cruciate ligament (ACL). This report describes a 55-year-old woman who experienced an avulsion fracture of the right anterior tibial eminence during recreational skiing. Sixteen months later, she presented at our hospital with limitation of right knee extension. Plain radiography showed nonunion of the avulsion fracture region, and arthroscopy showed that the avulsed fragment impinged the femoral intercondylar notch during knee extension. The anterior region of the bony fragment was debrided arthroscopically until the knee could be extended completely. There was no subsequent instability, and the patient was able to climb a mountain 6 months after surgery. These findings indicate that arthroscopic debridement of an avulsed fragment for nonunion of an avulsion fracture of the anterior tibial eminence is a minimally invasive and effective treatment for middle-aged and elderly patients with a low level of sports activity. PMID:27119035

High hip center reconstruction has been advocated in treating deficient acetabulum. However, there is no consensus on the clinical outcome of this technique. In addition, it remains unclear to what extend this technique restores the normal hip biomechanics. The goal of this study was to investigate stress above the acetabular dome in response to a range of high hip center positioning for Crowe type I and II hip dysplasia. This study consisted of 2 main parts, radiologic and biomechanical. Pelvic radiographs of 18 patients were studied to determine the amount of displacement of the hip center in the superior direction compared with the normal side. Second, qualitative and quantitative changes in stress on cortical and trabecular bone in the region of the acetabular dome as a result of superior displacement of the hip center were analyzed with subject-specific finite element models. The results showed that the range of the hip center position in the superior direction for Crowe type I and II hip dysplasia was 0 to 15 mm above the contralateral femoral head center. When superior displacement of the hip center exceeded 5 mm above the anatomic hip center, cortical bone mass on the 2 thickest cross-sections above the acetabular dome decreased quickly and the stress value on posterolateral cortical bone was obviously lower than the normal level. This study showed that to restore the normal load above the acetabular dome, there is a limit of 5 mm above the anatomic hip center for high hip center acetabular reconstruction for Crowe type I and II hip dysplasia. PMID:24992059

[Purpose] This study evaluated the effects of trunk-hip strengthening exercise on trunk-hip activation and pelvic tilt motion during standing in children with spastic diplegia and compared the improvement of pelvic tilt between the modified trunk-hip strengthening exercise and conventional exercise. [Subjects and Methods] Ten ambulant children with spastic diplegia were randomized to the modified trunk-hip strengthening exercise (n = 5) or conventional exercise (n = 5) group. The intervention consisted of a 6-week modified trunk-hip strengthening exercise 3 times per week. The children were tested for trunk-hip muscles activation and pelvic tilt motion during standing by surface electromyography and an inclinometer before and after the intervention. [Results] The anterior pelvic tilt angle and activation of the extensor spinae, rectus femoris, and semitendinosus during standing decreased significantly in the modified exercise group. The activation of extensor spinae differed significantly between groups. [Conclusion] Compared to the conventional exercise, the modified exercise was more effective for trunk-hip activation improvement and anterior pelvic tilt motion decrease during standing in children with spastic diplegia. We suggest clinicians use an individually tailored modified trunk-hip strengthening exercise for strengthening the weakest muscle groups in children with standing ability problems. PMID:26157214

The purpose of this study is to investigate the outcomes from anchor-induced chondral damage of the hip, both with and without frank chondral penetration. A multicenter retrospective case series was performed of patients with chondral deformation or penetration during initial hip arthroscopic surgery. Intra-operative findings, post-surgical clinical courses, hip outcome scores and descriptions of arthroscopic treatment in cases requiring revision surgery and anchor removal are reported. Five patients (three females) of mean age 32 years (range, 16–41 years) had documented anchor-induced chondral damage with mean 3.5 years (range, 1.5–6.0 years) follow-up. The 1 o'clock position (four cases) and anterior and mid-anterior portals (two cases each) were most commonly implicated. Two cases of anchor-induced acetabular chondral deformation without frank penetration had successful clinical and radiographic outcomes, while one case progressed from deformation to chondral penetration with clinical worsening. Of the cases that underwent revision hip arthroscopy, all three had confirmed exposed hard anchors which were removed. Two patients have had clinical improvement and one patient underwent early total hip arthroplasty. Anchor-induced chondral deformation without frank chondral penetration may be treated with close clinical and radiographic monitoring with a low threshold for revision surgery and anchor removal. Chondral penetration should be treated with immediate removal of offending hard anchor implants. Preventative measures include distal-based portals, small diameter and short anchors, removable hard anchors, soft suture-based anchors, curved drill and anchor insertion instrumentation and attention to safe trajectories while visualizing the acetabular articular surface. PMID:27011815

The purpose of this study is to investigate the outcomes from anchor-induced chondral damage of the hip, both with and without frank chondral penetration. A multicenter retrospective case series was performed of patients with chondral deformation or penetration during initial hip arthroscopic surgery. Intra-operative findings, post-surgical clinical courses, hip outcome scores and descriptions of arthroscopic treatment in cases requiring revision surgery and anchor removal are reported. Five patients (three females) of mean age 32 years (range, 16-41 years) had documented anchor-induced chondral damage with mean 3.5 years (range, 1.5-6.0 years) follow-up. The 1 o'clock position (four cases) and anterior and mid-anterior portals (two cases each) were most commonly implicated. Two cases of anchor-induced acetabular chondral deformation without frank penetration had successful clinical and radiographic outcomes, while one case progressed from deformation to chondral penetration with clinical worsening. Of the cases that underwent revision hip arthroscopy, all three had confirmed exposed hard anchors which were removed. Two patients have had clinical improvement and one patient underwent early total hip arthroplasty. Anchor-induced chondral deformation without frank chondral penetration may be treated with close clinical and radiographic monitoring with a low threshold for revision surgery and anchor removal. Chondral penetration should be treated with immediate removal of offending hard anchor implants. Preventative measures include distal-based portals, small diameter and short anchors, removable hard anchors, soft suture-based anchors, curved drill and anchor insertion instrumentation and attention to safe trajectories while visualizing the acetabular articular surface. PMID:27011815

Congenital anterior urethral diverticulum (CAUD) may be found all along the anterior urethra and may present itself at any age, from infant to adult. Most children with this condition present with difficulty in initiating micturition, dribbling of urine, poor urinary stream, or urinary tract infection. A careful history will reveal that these children never had a good urinary stream since birth, and the telltale sign is a cystic swelling of the penile urethra. In this paper, we present two cases of CAUD that were managed by excision of the diverticulum with primary repair. PMID:26328174

Background: Complications related to hip arthroscopy are rare, with a current rate of <2%. Some complications are related to fluid extravasation, which has been associated with life-threatening conditions such as abdominal compartment syndrome, cardiopulmonary arrest, hypothermia, and atelectasis. Purpose: To identify risk factors for fluid volume extravasation in hip arthroscopy and to determine the relationship between anatomical location on computed tomography (CT) and extravasated volume. Study Design: Case series; Level of evidence, 4. Methods: We performed a prospective cohort study of 40 consecutive arthroscopies for femoroacetabular impingement. Patient demographics and procedures performed (ie, acetabuloplasty and its size, femoral osteoplasty, and psoas tenotomy) were recorded. The extravasated volume was estimated by the difference between the infused volume and the intraoperatively collected volume. Within 12 hours after the procedure, the pelvis was scanned by CT. We created a 3-stage radiological classification based on progressive involvement of anatomical structures attributed to liquid extravasation. Statistical analyses were performed with a 95% CI and a significance level of 5%. Results: No relevant clinical symptoms related to fluid extravasation were recorded. The mean extravasated volume was 3.06 L at a rate of 1.05 L/h, corresponding to nearly 10% of the infused volume. There was a trend toward greater extravasated volume with longer operative time and longer time in the peripheral compartment (without axial traction); however, there was no statistical significance. The anatomical classification on CT imaging was directly related to the extravasated volume and compromised the thigh, gluteus, and retroperitoneum and intraperitoneal spaces. There was a 6-fold greater probability of female patients having an advanced stage extravasation on CT classification. Conclusion: In our series, 10% of the infused volume was extravasated in uncomplicated

Osteoarthritis (OA) of the hip is a common cause of hip pain. The arthroscopic management of patients with femoro-acetabular impingement (FAI) has been reported to yield good outcomes. The purpose of this study was to report on outcome following the arthroscopic treatment of patients with FAI in the presence of mild to moderate OA. Seventy-five patients undergoing arthroscopic surgery for FAI, all with preoperative radiological signs of mild to moderate OA were prospectively included in this study. A 2-year follow-up, using web-based patient-reported outcome measures, including the International Hip Outcome Tool (iHOT-12), Copenhagen Hip and Groin Outcome (HAGOS), EQ-5D, Hip Sports Activity Scale (HSAS) for physical activity level and a visual analogue scale (VAS) for overall hip function, was performed, complemented by a radiographic evaluation. At follow-up (mean 26 months, SD 5), five patients (7%) had undergone total hip arthroplasty, leaving 70 patients for the analysis. Preoperative scores compared with those obtained at the 2-year follow-up revealed significant improvements (P hip function (48 versus 68), HSAS (2.5 versus 3), EQ5D index (0.62 versus 0.76), EQ VAS (69 versus 75) and different HAGOS subscales (54 versus 72, 47 versus 67, 56 versus 75, 40 versus 61, 33 versus 56, 31 versus 55). At follow-up, 56 (82%) patients reported that they was satisfied with the outcome of surgery. Arthroscopic treatment for patients with FAI in the presence of mild to moderate OA resulted in statistically significant and clinically relevant improvements in outcome measures related to pain, symptoms, function, physical activity level and quality of life in the majority of patients. PMID:27026820

Pronounced aeroacoustic resonances are exhibited in the flowfield where a jet emerges from an orifice or a nozzle and impinges on a solid surface. One instance where such resonances are produced is in a high speed jet impingement, such as in the space launch vehicle systems, jet-engine exhaust impingement, and in the short take-off and vertical landing (STOVL) aircraft, etc. A highly unsteady flowfield leading to a drastic increase of noise level with very high dynamic pressure and thermal loads are noticed on nearby surfaces results dramatic lift loss, severe ground erosion and hot gas ingestion to the inlet in the jet engines. This highly unsteady behavior of the impinging jets is due to a feedback loop between the fluid and acoustic fields. In actual jet flow, the working gas may contain condensable gas such as steam or moist air. In these cases, the non-equilibrium condensation may occur at the region between nozzle exit and an object. The jet flow with non-equilibrium condensation may be quite different from that without condensation. Therefore, in this study, the effect of the non-equilibrium condensation of moist air on the axisymmetric under-expanded supersonic impinging jet on a vertical flat plate was investigated numerically.

Mean and fluctuating surface pressure data were obtained in a Mach 8, turbulent, cold flow past an expansion corner subjected to shock impingement. The expansion corner of 2.5 or 4.25 deg was located at 0.77 m (30.25 in.) from the leading edge of a shape-edged flat plate while an external shock, generated by either a 2- or 4-deg sharp wedge, impinged at the corner, or at one boundary layer thickness ahead or behind the corner. The mean pressure distribution was strongly influenced by the mutual interaction between the shock and the expansion. For example, the upstream influence decreased when the shock impinged downstream of the corner. Also, the unsteadiness of the interactions was characterized by an intermittent region and a local rms pressure peak near the upstream influence line. The peak rms pressure fluctuations increased with a larger overall interaction strength. Shock impingement downstream of the corner resulted in lower peaks and also in a shorter region of reduced fluctuation levels. These features may be exploited in inlet design by impinging the cowl shock downstream of an expansion corner instead of at the corner. In addition, a limited Pitot pressure survey showed a thinning of the boundary layer downstream of the corner.

The initial shear layer characteristics of a jet play an important role in the initiation and development of instabilities and hence radiated noise. Particle image velocimetry has been utilized to study the initial shear layer development of supersonic free and impinging jets. Microjet control employed to reduce flow unsteadiness and jet noise appears to affect the development of the shear layer, particularly near the nozzle exit. Velocity field measurements near the nozzle exit show that the initially thin, uncontrolled shear layer develops at a constant rate while microjet control is characterized by a rapid nonlinear thickening that asymptotes downstream. The shear layer linear growth rate with microjet control, in both the free and the impinging jet, is diminished. In addition, the thickened shear layer with control leads to a reduction in azimuthal vorticity for both free and impinging jets. Linear stability theory is used to compute unstable growth rates and convection velocities of the resultant velocity profiles. The results show that while the convection velocity is largely unaffected, the unstable growth rates are significantly reduced over all frequencies with microjet injection. For the case of the impinging jet, microjet control leads to near elimination of the impingement tones and an appreciable reduction in broadband levels. Similarly, for the free jet, significant reduction in overall sound pressure levels in the peak radiation direction is observed.

A series of experiments were performed to explore the effects of forcing frequency in controlling an ideally expanded Mach 1.3 axisymmetric impinging jet operating in a strong resonance regime. The Hartmann Tube Fluidic Actuator (HTFA), which is an actuator with high bandwidth and high amplitude characteristics, was used for the forcing. Three HTFAs with zero frequency (steady injection), low frequency of 5.4 kHz (near the impinging jet resonance frequency of 5.3 kHz), and high frequency of 12 kHz were used. Measurements were performed to characterize the near- and far-field acoustic of the unforced and forced jets. Detailed flow visualization is currently being used to correlate changes in the acoustic field with changes in the large-scale coherent structures. The results show that using steady injection and high frequency forcing behave similarly in suppressing the impingement tone, but both raise the broadband acoustic level around the impingement tone. The low frequency forcing also suppresses the impingement tone but with less rise in the broadband noise. Both the high frequency and low frequency forcing leave their imprint at the forcing frequency.

Objective: To review current concepts of the pathophysiology, diagnosis, and treatment of rotator cuff and impingement injuries in the athlete. Data Sources: The information we present was compiled from a review of classic and recently published material regarding rotator cuff and impingement injuries. These materials were identified through a search of a personal literature database compiled by the authors, as well as by selective searching of the MEDLINE. In addition, much of the information presented represents observations and opinions of the authors developed over 8 to 10 years of treating shoulder injuries in athletes. Data Synthesis: Biomechanics of the normal shoulder and pathophysiology of rotator cuff injuries in the athletic population are discussed, followed by a summary of the important diagnostic features of rotator cuff and impingement injuries. The principles of rehabilitation are extensively presented, along with indications and important technical aspects of selected surgical procedures. General principles and specific protocols of postoperative rehabilitation are also summarized. Conclusions/Recommendations: Rotator cuff and impingement injuries in the athletic population are multifactorial in etiology, exhibiting significant overlap with glenohumeral instability. Nonoperative treatment is successful in most athletic patients with rotator cuff and impingement injuries. When nonoperative treatment fails, arthroscopic surgical techniques such as rotator cuff repair and subacromial decompression may be successful in returning the athlete to competition. ImagesFigure 2.Figure 3.Figure 4.Figure 5.Figure 6.Figure 7.Figure 8.Figure 9.Figure 10.Figure 11.Figure 12.Figure 13. PMID:16558644

An investigation into the development of flow unsteadiness in impinging axisymmetric underexpanded jets has been conducted at NASA Langley Research Center. The study has examined the effect of an impingement target placed at various distances and angles on transitional behavior of such jets. Two nozzles, with exit Mach numbers of 1.0 and 2.6, were used in this investigation. Planar laser-induced fluorescence of nitric oxide (NO PLIF) has been used to identify flow unsteadiness and to image transitional and turbulent flow features. Measurements of the location of the onset of various degrees of unsteady flow behavior have been made using these PLIF images. Both qualitative and quantitative comparisons are presented to demonstrate the observed effects of impingement and flow parameters on the process of the transition to turbulence. The presence of the impingement target was found to significantly shorten the distance to transition to turbulence by up to a factor of approximately three, with closer targets resulting in slightly shorter distance to transition and turbulence. The location at which the flow first exhibits unsteadiness was found to have a strong dependence on the presence and location of key flow structures. This paper presents quantitative results on transition criteria for free and impinging jets.

Background: There is limited research regarding the epidemiology of hip/groin injuries in ice hockey, the majority of which is restricted to time-loss injuries only. Purpose: To describe the epidemiology of hip/groin injuries in collegiate men’s and women’s ice hockey from 2009-2010 through 2014-2015. Study Design: Descriptive epidemiology study. Methods: Hip/groin injury data from the National Collegiate Athletic Association Injury Surveillance Program (NCAA-ISP) during the 2009-2010 through 2014-2015 seasons were analyzed. Injury rates, rate ratios (RRs), and injury proportion ratios (IPRs) were reported with 95% confidence intervals (CIs). Results: During the 2009-2010 through 2014-2015 seasons, 421 and 114 hip/groin injuries were reported in men’s and women’s ice hockey, respectively, leading to injury rates of 1.03 and 0.78 per 1000 athlete-exposures (AEs), respectively. The hip/groin injury rate was greater in men than in women (RR, 1.32; 95% CI, 1.08-1.63). In addition, 55.6% and 71.1% of hip/groin injuries in men’s and women’s ice hockey, respectively, were non–time loss (NTL) injuries (ie, resulted in participation restriction time <24 hours); 7.6% and 0.9%, respectively, were severe (ie, resulted in participation restriction time >3 weeks). The proportion of hip/groin injuries that were NTL injuries was greater in women than in men (IPR, 1.28; 95% CI, 1.11-1.48). Conversely, the proportion of hip/groin injuries that were severe was greater in men than in women (IPR, 8.67; 95% CI, 1.20-62.73). The most common hip/groin injury diagnosis was strain (men, 67.2%; women, 76.3%). Also, 12 (2.9%) and 3 (2.6%) cases of hipimpingement were noted in men’s and women’s ice hockey, respectively. Conclusion: Hip/groin injury rates were greater in men’s than in women’s ice hockey. Time loss varied between sexes, with men sustaining more injuries with time loss over 3 weeks. Despite increasing concerns of femoroacetabular impingement in ice hockey

The differences between prostheses fixed with and without cement are mainly in the design and nature of the surface implant. The shapes of the sockets to be implanted without cement show a wide variety: cylinder, square, conus, and ellipsoid with and without threads. The hemispheric shape, however, which was chosen for the acetabular component of the isoelastic hip joint, does not disturb the natural form and function of the hip joint since the outer surface is closely adapted to the original subchondral bone layer. The noncemented cup is secured by threads, pegs, screws, etc., and by ingrowth of bony tissue in the grooves of the surfaces. Most femoral stems are based on the self-locking principle. All prosthetic models incorporate attempts to increase the surface of the stem (ribs, wings, corrugations, rims, etc.). There is a tendency to use less rigid elastic implants instead of the well known rigid metallic prostheses. The aim is to overcome the problems of stress protection and stress concentration observed with rigid implants. For the biomechanical integration of an implant, the properties of the surface, especially macroporosity and microporosity, are important. Most European models of noncemented endoprostheses are based on macroporosity (porometal, madreporic, etc.). The increase in implant surface area achieved with macroscopic perforations and recesses is relatively minor compared with the possibilities offered by microporosity ("alumine fritée," Proplast, fiber-metal, etc.). The best indication for use of a cementless hip endoprosthesis is in revision arthroplasty. The lost bone stock is replaced by bone grafts, thereby creating a situation comparable with that of a primary arthroplasty. Clinical experience with noncemented hip endoprostheses is, to date, promising, although the observation time for most models is short. PMID:6357588

Toxic anterior segment syndrome (TASS) is a general term used to describe acute, sterile postoperative inflammation due to a non-infectious substance that accidentally enters the anterior segment at the time of surgery and mimics infectious endophthalmitis. TASS most commonly occurs acutely following anterior segment surgery, typically 12-72h after cataract extraction. Anterior segment inflammation is usually quite severe with hypopyon. Endothelial cell damage is common, resulting in diffuse corneal edema. No bacterium is isolated from ocular samples. The causes of TASS are numerous and difficult to isolate. Any device or substance used during the surgery or in the immediate postoperative period may be implicated. The major known causes include: preservatives in ophthalmic solutions, denatured ophthalmic viscosurgical devices, bacterial endotoxin, and intraocular lens-induced inflammation. Clinical features of infectious and non-infectious inflammation are initially indistinguishable and TASS is usually diagnosed and treated as acute endophthalmitis. It usually improves with local steroid treatment but may result in chronic elevation of intraocular pressure or irreversible corneal edema due to permanent damage of trabecular meshwork or endothelial cells. PMID:21176994

Future missions to the Moon may require numerous landings at the same site. Since the top few centimeters are loosely packed regolith, plume impingement from the Lander ejects the granular material at high velocities. Much work is needed to understand the physics of plume impingement during landing to protect hardware surrounding the landing sites. While mostly qualitative in nature, the Apollo Lunar Module landing videos can provide a wealth of quantitative information using modern photogrammetry techniques. The authors have used the digitized videos to quantify plume impingement effects of the landing exhaust on the lunar surface. The dust ejection angle from the plume is estimated at 1°-3°. The lofted particle density is estimated at 10 8-10 13 particles/m 3. Additionally, evidence for ejection of large 10-15 cm sized objects and a dependence of ejection angle on thrust are presented. Further work is ongoing to continue quantitative analysis of the landing videos.

Each of the six Apollo mission landers touched down at unique sites on the lunar surface. Aside from the Apollo 12 landing site located 180 meters from the Surveyor III lander, plume impingement effects on ground hardware during the landings were largely not an issue. The Constellation Project's planned return to the moon requires numerous landings at the same site. Since the top few centimeters are loosely packed regolith, plume impingement from the lander ejects the granular material at high velocities. With high vacuum conditions on the moon (10 (exp -14) to 10 (epx -12) torr), motion of all particles is completely ballistic. Estimates from damage to the Surveyor III show that the ejected regolith particles to be anywhere 400 m/s to 2500 m/s. It is imperative to understand the physics of plume impingement to safely design landing sites for the Constellation Program.

The painful arc syndrome may be produced by impingement of the supraspinatus tendon, the biceps tendon, or the greater tuberosity of the humerus against the coracoacromial arch. Where conservative measures have failed, surgical intervention may provide considerable symptomatic relief by decompressing the coracoacromial arch. In 20 cases surgically treated for biceps or supraspinatus impingements, 17 patients have returned to sporting activities without symptoms. The painful arc syndrome persists in three patients but they are symptomatically improved. Six patients with complete rotator cuff tears and subsequent impingement of the greater tuberosity of the humerus against the coracoacromial arch underwent widespread decompression. Five of the patients have returned to sporting activities much improved. Failure to recognize the associated acromioclavicular joint pathology is a frequent cause of failure of surgical treatment. PMID:7468889

Heterotopic ossification (HO) after hip arthroscopy is the abnormal formation of mature lamellar bone within extra skeletal soft tissues. HO may lead to pain, impaired range of motion and possibly revision surgery. There has been a substantial amount of recent research on the pathophysiology, prophylaxis and treatment of HO associated with open and arthroscopic hip surgery. This article reviews the literature on the aforementioned topics with a focus on their application in hip arthroscopy. PMID:27011859

Heterotopic ossification (HO) after hip arthroscopy is the abnormal formation of mature lamellar bone within extra skeletal soft tissues. HO may lead to pain, impaired range of motion and possibly revision surgery. There has been a substantial amount of recent research on the pathophysiology, prophylaxis and treatment of HO associated with open and arthroscopic hip surgery. This article reviews the literature on the aforementioned topics with a focus on their application in hip arthroscopy. PMID:27011859

Introduction: The posterior approach is the most commonly and relatively easy to be used to expose the hip joint. Posterior approaches allow excellent visualization of the entire acetabulum and the upper femoral shaft, and thus they are popular for revision joint replacement surgery particularly in cases where only the femoral component needs to be replaced. There may be a higher dislocation rate with minimal movement as compared to anterior approaches if the posterior approach is used in fractured neck of femur surgery in demented or elderly bedridden patients who often lie crouched in bed with their hips in a flexed and adducted position. The expected purpose of this modification of the Posterior Approach to the Hip Joint is to overcome the fear of dislocation and hence combine the advantages of the Posterior route with greater stability. Technique: The author’s original paper written 30 years ago (Iyer, 1981) presented an original technique devised to confer greater stability to the hip joint posteriorly to minimize the greater incidence of dislocation which has been reported extensively in literature. The technique involves an osteotomy of the posterior overhanging part of the greater trochanter to include the insertions of the short lateral rotators along with the posterior third of the gluteus medius, which can then be turned back in one piece like the page of a book to include the capsule of the hip joint. This gives wide exposure of the posterior lip of the acetabulum and is relatively bloodless in its exposure. This approach is very useful in the elderly particularly demented patients requiring a hemiarthroplasty and also in primary and revision total hip replacement. This approach has been tested in cadavers to conclude the greater stability given as compared to the routine resuture or reattachment of the short lateral rotators. Conclusion: The modified technique provides for greater stability as compared to the Southern Approach. PMID:27299026

The hip capsule is a highly complex anatomic structure, which influences normal hip motion and biomechanics. A dynamic stabilizing capsular contribution exists in the iliocapsularis and gluteus minimus, among other musculotendinous structures crossing the joint. Variable types and sizes of capsulotomy are necessary to sufficiently visualize and address the bony and soft tissue pathologic source of symptoms. Unrepaired capsulotomies may leave the hip significantly unstable to variable degrees. Capsular closure is a necessary part of a comprehensive arthroscopic hip preservation procedure. Greater titration of the degree of plication may be performed for patients with risk factors for postoperative instability. PMID:27343391

Sonography of the infant hip has gained wide acceptance in the decade since its introduction. The two principle techniques of Graf and Harcke have been combined with the proposal of a Dynamic Standard Minimum Examination. Whereas sonography is used increasingly to manage developmental dislocation and/or displasia of the hip, there is no agreement on the use of sonography for universal newborn screening. This article describes in detail the Dynamic Standard Minimum Sonographic Examination of the infant hip. In addition, this article reviews the classification and management of infant hip disorders. PMID:7946476

Femoroacetabular impingement and dysplatic hip joint is well known cause of osteoarthritis. In these diseases, labral tear and subsequent cartilage damage is thought to be main pathophysiology of development of osteoarthritis. If there are no known bony abnormalities, we called it as idiopathic osteoarthritis. Normal appearance of acetabular labrum is a continuous, usually triangular structure that attaches to the bony rim of the acetabulum and is completed at the inferior portion by the transverse acetabular ligament over the acetabular notch. A few authors reported intra-articular labrum and its relation to the development of osteoarthritis. But they didn't comment the primary bony abnormality especially acetabulum. We'd like to report x-ray, computed tomogram, magnetic resonance arthrogram and arthroscopic findings of a case had double contour sign of acetabular dome combined with intrusion of acetabular labrum.

Heat transfer devices and methods for making the same that include a first enclosure having at least one inlet port; a second enclosure having a bottom plate and one or more dividing walls to establish channels, at least one internal surface of each channel having rib structures to create turbulence in a fluid flow; and a jet plate connecting the first enclosure and the second enclosure having impinging jets that convey fluid from the first enclosure to the channels, said impinging jets being set at an angular deviation from normal to cause local acceleration of fluid and to increase a local heat transfer rate.

Measurements were made of the local heat transfer at the surface of a flat plate underneath a confined impinging jet. Thermochromic liquid crystals were used to measure the surface temperature of a uniformly heated plate cooled by an impinging jet. The temperature of the wall through which the jet passes was controlled, and experiments were performed to measure the two heat transfer coefficients which arise from this three temperature problem. The effect of Reynolds number and plate to jet spacing on heat transfer was investigated. The heat transfer results are discussed in terms of the interpreted flow field.

Subacromial impingement is a condition that belongs to the group of diseases known collectively as periarthritis humeroscapularis and has a typical clinical presentation. The underlying cause is a late of sufficient space of various origin in the subacromial region that finally leads to rotator cuff damage. Depending on cause, three forms can be distinguished, primarily extrinsic, primarily intrinsic and secondary impingement. The diagnosis is primarily clinical (pain on raising the arms above the head, painful arc syndrome). The value of imaging techniques, and the diagnostic approach are described. Initially treatment is always conservative, but when pain becomes severe or function is lost, arthroscopic or open surgical treatment may be needed. PMID:7607595

The phenomenon of supersonic jets and their interaction with solid surfaces is found in many engineering applications such as impingement of exhaust from launch vehicles during the liftoff phase, during stage separation of multistage rockets, and VTOL/STOL operation of aircraft, etc. In this paper, experimental and numerical studies are carried out to investigate impingement flowfield produced on a typical axisymmetric jet deflector. The experiments consisted of schlieren flow visualization and measurements of pressure. The present study will be useful for the design of a typical axisymmetric jet deflector during the liftoff phase of a rocket.

... developmental dysplasia (dislocation) of the hip (DDH), the hip joint has not formed normally. The ball is loose ... be taken to provide detailed pictures of the hip joint. Treatment When DDH is detected at birth, it ...

Introduction Not many investigations have evaluated the relationship between the height of the interdental papillae, gingival zenith and maxillary anterior teeth. The assessment of these parameters can aid in fabricating definitive aesthetic restoration. Aim The aim of this study was to evaluate the existence of proportional ratio between the incisal edge to gingival zenith (HGZ) and the tip of the interdental papilla (HIP) in maxillary anterior teeth for Indian population. Materials and Methods One hundred healthy volunteers with an average age of 25-30 years comprised the evaluation group. Impression was made using irreversible hydrocolloid impression material and type IV Dental stone cast was made. A calibrated digital caliper measured the distance between HGZ and HIP. The values for all six maxillary teeth were recorded and the proportional ratio was evaluated and statistically analysed. Results The mean ratio between HGZ and HIP of all maxillary anteriors in 1st and 2nd quadrant was 1.80, 1.71, and 2.03 in central incisor, lateral incisor and canine respectively with p-value > 0.9. Conclusion The mean proportional measurements for maxillary anterior teeth were determined and no definitive proportion existed between HGZ and HIP of maxillary anterior teeth. PMID:27134999

Introduction: Catastrophic polyethylene failure is a rare complication of ceramic-on-polyethylene total hip arthroplasty due to the favorable tribological characteristics of ceramic. Failure of the polyethylene liner can be disastrous, increasing periprosthetic osteolysis, metallosis, and risk of dislocation. Complications associated with ceramic-on-polyethylene articulations have been studied extensively, however, only few reports have described its catastrophic wear. We report such a case of complete wear of the acetabular liner in a ceramic-on-polyethylene prosthesis in a 57-year adult male. Case Report: A 57-year adult male with a history of bilateral total hip arthroplasty presented to our institution with bilateral hip pain worst on the right. Range of motion was limited by pain on the right hip at the extremes of motion. Radiographs revealed severe osteolysis, heterotopic ossification, complete wear of the acetabular liner, bony impingement of the femoral greater trochanter on the acetabular rim and superior migration of the femoral head. All findings were confirmed intraoperatively. Revision of the acetabular components was performed, which successfully alleviated the patient’s symptoms. Conclusion: Failure of the ceramic-on-polyethylene liner in our patient is due to the use of a non-cross linked polyethylene liner, a highly active lifestyle, and poor follow up. Arthroplasty surgeons should be aware of this complication especially in highly active patients with a conventional polyethylene liner and chronic hip pain. PMID:27298960

The patient with an unstable slipped capital femoral epiphysis poses a challenging problem to the treating physician to improve the position of the displaced epiphysis to avoid femoroacetabular impingement without developing avascular necrosis (AVN)-a potentially devastating complication. Although the standard operative procedure of in situ pinning following an incidental reduction while positioning the patient on the table, has been the mainstay of treatment in North America, other viable options are available including a surgical dislocation approach to the hip followed by a modified Dunn osteotomy with control of the retinacular vessels, reduction of the epiphysis, and internal fixation with pins or screws. Although technically demanding, this approach offers an opportunity to reduce the epiphysis to avoid femoroacetabular impingement, and limit the possibility for the development of AVN. The early results for this procedure are promising with all studies demonstrating excellent reduction of the epiphysis and an overall lower incidence of AVN when compared with in situ pinning. PMID:25207732

Summary Objective To estimate the lifetime risk of symptomatic hip osteoarthritis (OA). Design We analyzed data from the Johnston County Osteoarthritis Project (a longitudinal population-based study of OA in North Carolina, United States [n=3,068]). The weighted baseline sample comprised 18% blacks and 54% women, and the mean age was 63 years (range=45-93). Symptomatic hip OA was defined as a Kellgren-Lawrence (K-L) radiographic score of ≥2 (anterior-posterior pelvis x-rays) and pain, aching or stiffness on most days, or groin pain, in the same hip. Lifetime risk, defined as the proportion who developed symptomatic hip OA in at least one hip by age 85, among people who live to age 85, was modeled using logistic regression with repeated measures (through generalized estimating equations). Results Lifetime risk of symptomatic hip OA was 25.3% (95% confidence interval [CI] = 21.3–29.3). Lifetime risk was similar by sex, race, highest educational attainment, and hip injury history. We studied lifetime risk by body mass index (BMI) in three forms: at age 18; at baseline and follow-up; and at age 18, baseline and follow-up and found no differences in estimates. Conclusion The burden of symptomatic hip OA is substantial with one in four people developing this condition by age 85. The similar race-specific estimates suggest that racial disparities in total hip replacements are not attributable to differences in disease occurrence. Despite increasing evidence that obesity predicts an increased risk of both hip OA and joint replacement, we found no association between BMI and lifetime risk. PMID:20713163

Deficits in proximal hip strength or neuromuscular control may lead to dynamic lower extremity valgus. Measures of dynamic lower extremity valgus have been previously shown to relate to increased risk of several knee pathologies, specifically anterior cruciate ligament ruptures and patellofemoral pain. Therefore, hip-focused interventions have gained considerable attention and been successful in addressing these knee pathologies. The purpose of the review was to identify and discuss hip-focused exercise interventions that aim to address dynamic lower extremity valgus. Previous electromyography, kinematics, and kinetics research support the use of targeted hip exercises with non-weight-bearing, controlled weight-bearing, functional exercise, and, to a lesser extent, dynamic exercises in reducing dynamic lower extremity valgus. Further studies should be developed to identify and understand the mechanistic relationship between optimized biomechanics during sports and hip-focused neuromuscular exercise interventions. PMID:26346471

Deficits in proximal hip strength or neuromuscular control may lead to dynamic lower extremity valgus. Measures of dynamic lower extremity valgus have been previously shown to relate to increased risk of several knee pathologies, specifically anterior cruciate ligament ruptures and patellofemoral pain. Therefore, hip-focused interventions have gained considerable attention and been successful in addressing these knee pathologies. The purpose of the review was to identify and discuss hip-focused exercise interventions that aim to address dynamic lower extremity valgus. Previous electromyography, kinematics, and kinetics research support the use of targeted hip exercises with non-weight-bearing, controlled weight-bearing, functional exercise, and, to a lesser extent, dynamic exercises in reducing dynamic lower extremity valgus. Further studies should be developed to identify and understand the mechanistic relationship between optimized biomechanics during sports and hip-focused neuromuscular exercise interventions. PMID:26346471

Ameloblastoma is a benign odontogenic tumor. These are usually asymptomatic until a large size is attained. Ameloblastoma has tendency to spread locally and has a high recurrence rate. Majority of ameloblastomas (80%) arise from the mandible. Ameloblastoma arising from anterior mandibular region (symphysis-menti) is rare. Very few cases of midline anterior ameloblastomas are reported in the literature. They often require wide local excision. Reconstruction of mandible in these cases is challenging. We present a case of mandibular ameloblastoma arising from symphysis-menti. Patient underwent wide surgical excision of the tumor followed by immediate reconstruction using free fibular vascular flap, stabilized with titanium reconstructive plates. A brief case report ands review of literature is presented. PMID:24765429

Male anterior urethral stricture disease is a commonly encountered condition that presents to many urologists. According to a National Practice Survey of Board Certified Urologist in the United States most urologists treat on average 6-20 urethral strictures yearly. Many of those same urologists surveyed treat with repeated dilation or internal urethrotomy, despite continual recurrence of the urethral stricture. In point of fact, the urethroplasty despite its high success rate, is underutilized by many practicing urologists. Roughly half of practicing urologist do not perform urethroplasty in the United States. Clearly, the reconstructive ladder for urethral stricture management that was previously described in the literature may no longer apply in the modern era. The following article reviews the etiology, diagnosis, management and comparisons of treatment options for anterior urethral strictures. PMID:26816721

Objective To correlate the angles between the acetabulum and the proximal femur in symptomatic patients with femoroacetabular impingement (FAI), using computed tomography (CT). Methods We retrospectively evaluated 103 hips from 103 patients, using multislice CT to measure the acetabular age, acetabular version (in its supraequatorial portion and in its middle third), femoral neck version, cervical-diaphyseal and alpha angles and the acetabular depth. For the statistical analysis, we used the Pearson correlation coefficient. Results There were inverse correlations between the following angles: (1) acetabular coverage versus alpha angle (p = 0.019); (2) acetabular version (supraequatorial) versus alpha angle (p = 0.049). For patients with femoral anteversion lower than 15 degrees: (1) acetabular version (supraequatorial) versus alpha angle (p = 0.026); (2) acetabular version (middle third) versus alpha angle (p = 0.02). For patients with acetabular version (supraequatorial) lower than 10 degrees: (1) acetabular version (supraequatorial) versus alpha angle (p = 0.004); (2) acetabular version (middle third) versus alpha angle (p = 0.009). Conclusion There was a statistically significant inverse correlation between the acetabular version and alpha angles (the smaller the acetabular anteversion angle was, the larger the alpha angle was) in symptomatic patients, thus supporting the hypothesis that FAI occurs when cam and pincer findings due to acetabular retroversion are seen simultaneously, and that the latter alone does not cause FAI, which leads to overdiagnosis in these cases. PMID:27069890

Introduction: Patellofemoral pain syndrome (PFPS) is characterized by anterior knee pain, which may limit the performance of functional activities. The influence of hip joint motion on the development of this syndrome has already been documented in the literature. In this regard, studies have investigated the effectiveness of hip muscle strengthening in patients with PFPS. Objectives: The aims of this systematic review were (1) to summarize the literature related to the effects of hip muscle strengthening on pain intensity, muscle strength, and function in individuals with PFPS and (2) to evaluate the methodological quality of the selected studies. Method: A search for randomized controlled clinical trials was conducted using the following databases: Google Scholar, MEDLINE, PEDro, LILACS, and SciELO. The selected studies had to distinguish the effects of hip muscle strengthening in a group of patients with PFPS, as compared to non-intervention or other kinds of intervention, and had to investigate the following outcomes: pain, muscle strength, and function. The methodological quality of the selected studies was analyzed by means of the PEDro scale. Results: Seven studies were selected. These studies demonstrated that hip muscle strengthening was effective in reducing pain. However, the studies disagreed regarding the treatments' ability to improve muscle strength. Improvement in functional capabilities after hip muscle strengthening was found in five studies. Conclusion: Hip muscle strengthening is effective in reducing the intensity of pain and improving functional capabilities in patients with PFPS, despite the lack of evidence for its ability to increase muscle strength. PMID:26039034

Each year we treat several patients with an anterior perineal sinus tract. They do not conform to commonly encountered perineal problems such as pilonidal disease, epidermal cysts, hidradenitis, fistulous abscess, or inflammatory bowel disease. In an effort to improve understanding of the problem and its clinical significance, we reviewed our practice records for the period from 1968 through 1988. Fifty-six patients underwent surgery for an anterior perineal sinus tract. In 31 patients, the clinical and pathologic condition defied classical diagnostic categorization. We have termed these lesions "anterior perineal sinuses." Their clinical characteristics, treatment, and pathologic assessment from the body of this report. Male predominance (87 percent) and midlife presentation (average age, 44 years) characterized this group. Local symptoms were present from several weeks to several years prior to treatment. Local anesthesia (74 percent) and limited surgery (100 percent) resulted in complete healing in all patients (average, 7 weeks). A 15 percent recurrence rate was noted. The pathologic evaluation demonstrated acute and chronic dermal and subcutaneous inflammation. The etiology of this process remains uncertain. Its predominance along the median raphe suggests a congenital midline inclusion disorder. PMID:1914743

Complex deformities of the acetabulum are one of the most common reasons for secondary pelvic osteoarthritis. One option of treatment is osteotomy of the acetabulum close to the joint. The correction of the spatially reduced roof of the femoral head resulting from pelvic dysplasia can minimize the risk of developing secondary osteoarthritis or reduce the progression of an already existing osteoarthritis. The Ganz periacetabular osteotomy (PAO) and Tönnis triple osteotomy procedures are the predominant methods used to correct hip dysplasia in adolescents. Both are complex procedures which bear specific risks and complications, thus requiring very experienced surgeons. PMID:24356819

Cavitation-erosion experimental data previously covering several materials tested in a rotating disk device and a magnetostriction apparatus were analyzed using new normalization and curve-fitting techniques. From this process a universal approach is derived which can include data from cavitation and liquid impingement studies for specific materials from different test devices.

Textured surfaces having an array of microscale pillars have been receiving large attention because of their potential uses for robust superhydrophobic and superoleophobic surfaces. In many practical applications, the textured surfaces usually accompany impinging small-scale droplets. To better understand the impinging phenomena on the textured surfaces, the wetting and spreading behaviors of water microdroplets are investigated experimentally. Microdroplets with diameter less than 50 μm are ejected from a piezoelectric printhead with varying Weber number. The final wetting state of an impinging droplet can be estimated by comparing the wetting pressures of the droplet and the capillary pressure of the textured surface. The wetting behaviors obtained experimentally are well agreed with the estimated results. In addition, the transition from bouncing to non-bouncing behaviors in the partially penetrated wetting state is observed. This transition implies the possibility of withdrawal of the penetrated liquid from the inter-pillar space. The maximum spreading factors (ratio of the maximum spreading diameter to the initial diameter) of the impinging droplets have close correlation with the texture area fraction of the surfaces. This work was supported by Creative Research Initiatives (Diagnosis of Biofluid Flow Phenomena and Biomimic Research) of MEST/KOSEF.

Experimental and numerical studies are carried out to investigate impingement flowfield produced on a typical axisymmetric jet deflector. The experiments consisted of schlieren flow visualization and measurements of pressure. The present study will be useful for the design of a typical axisymmetric jet deflector during the liftoff phase of a rocket.

In connection with the conduction of the long-duration Voyager missions to the outer planets and the sophisticated propulsion systems required, it was necessary to carry out an investigation to avoid exhaust plume impingement problems. The rarefied gas dynamics literature indicates that, for most engineering surfaces, the assumption of diffuse reemission and complete thermal accommodation is warranted in the free molecular flow regime. This assumption was applied to an analysis of a spacecraft plume impingement problem in the near-free molecular flow regime and yielded results to within a few percent of flight data. The importance of a correct treatment of the surface temperature was also demonstrated. Specular reflection, on the other hand, was shown to yield results which may be unconservative by a factor of 2 or 3. It is pointed out that one of the most difficult portions of an exhaust plume impingement analysis is the simulation of the impinged hardware. The geometry involved must be described as accurately and completely as possible.

Hip-hop music and culture are often cited as being public pedagogy, meaning the music itself has intrinsic educational value. Non-profit organizations and individual educators have graciously taken the lead in utilizing hip-hop to educate. As the academy continues to debate its effectiveness, teachers and community organizers are moving forward.…

The collection efficiency of liquid impingers was studied experimentally as a function of the sampling flow rate with test particles in the bacterial size range. Three impingers were tested: two All-Glass Impingers(AGI-4 and AGI-30),widely used for bioaerosol sampling, and a newl...

The objective of this contract was to continue development of a vacuum plume impingement evaluator to provide an analyst with a capability for rapid assessment of thruster plume impingement scenarios. The research was divided into three areas: Plume Impingement Computer Program (PLIMP) modification/validation; graphics development; and documentation in the form of a Plume Handbook and PLIMP Input Guide.

We report on gender-specific reference intervals of the alpha angle and its association with other qualitative cam-type findings in femoroacetabular impingement at the hip, according to a population-based cohort of 2038 19-year-olds, 1186 of which were women (58%). The alpha angle was measured on standardised frog-leg lateral and anteroposterior (AP) views using digital measurement software, and qualitative cam-type findings were assessed subjectively on both views by independent observers. In all, 2005 participants (837 men, 1168 women, mean age 18.6 years (17.2 to 20.1) were included in the analysis. For the frog-leg view, the mean alpha angle (right hip) was 47° (26 to 79) in men and 42° (29 to 76) in women, with 97.5 percentiles of 68° and 56°, respectively. For the AP view, the mean values were 62° (40 to 105) and 52° (36 to 103) for men and women, respectively, with 97.5 percentiles of 93° and 94°. Associations between higher alpha angles and all qualitative cam-type findings were seen for both genders on both views. The reference intervals presented for the alpha angle in this cross-sectional study are wide, especially for the AP view, with higher mean values for men than women on both views. PMID:24692609

Percutaneous screw fixation of the anterior column of the acetabulum has been a challenging task because of its unique anatomy and a risk of intra-articular penetration. Evidence is lacking for any tools to provide visual scrutiny of fracture reduction and intra-articular screw penetration. We report 2 cases of fracture of the acetabulum that developed in young female athletes, in which the anterior column was fixed with a percutaneous screw by use of hip arthroscopy as an assisting tool for intra-articular observation. In our experience this method was found to be promising in terms of anatomic reduction of the fracture site, avoiding articular penetration during screw insertion, with additional advantages of joint debridement, lavage, and reduction in radiation exposure. PMID:20888169

Tendon transfer procedures are used commonly for the correction of soft tissue imbalances and instabilities. The complete transfer and the split transfer of the tibialis anterior tendon are well-accepted methods for the treatment of idiopathic equinovarus deformity in children and adults. Throughout the literature, complete and split transfer have been shown to yield significant improvements in ankle and foot range of motion and muscle function. At present, there is insufficient evidence to recommend one procedure over the other, although the split procedure has been advocated for consistently achieving inversion to eversion muscle balance without overcorrection. PMID:26590723

A 16-year old male patient visited the hospital complaining of inguinal pain and internal snapping of right hip joint. In physical examination, the patient was presumed to be diagnosed femoroacetabular impingement (FAI) and acetabular labral tear. In radiologic evaluation, FAI and acetabular labral tear were identified and bony tumor associated with internal snapping was found on the posteromedial portion of the femoral neck. Despite of conservative treatment, there was no symptomatic improvement. So arthroscopic labral repair, osteoplasty and resection of bony tumor were performed. The tumor was pathologically diagnosed as osteochondroma through biopsy and all symptoms improved after surgery. There was no recurrence, complication or abnormal finding during 1 year follow up. Osteochondroma located at posteromedial portion of femoral neck can be a cause of internal snapping hip and although technical demands are challenging, arthroscopic resection can be a good treatment option.

Abstract Context: Reduced hip-abductor strength and muscle activation may be associated with altered lower extremity mechanics, which are thought to increase the risk for anterior cruciate ligament injury. However, experimental evidence supporting this relationship is limited. Objective: To examine the changes in single-leg landing mechanics and gluteus medius recruitment that occur after a hip-abductor fatigue protocol. Design: Descriptive laboratory study. Patients or Other Participants: Twenty physically active women (age = 21.0 ± 1.3 years). Intervention(s): Participants were tested before (prefatigue) and after (postfatigue) a hip-abductor fatigue protocol consisting of repetitive side-lying hip abduction. Main Outcome Measure(s): Outcome measures included sagittal-plane and frontal-plane hip and knee kinematics at initial contact and at 60 milliseconds after initial contact during 5 single-leg landings from a height of 40 cm. Peak hip and knee sagittal-plane and frontal-plane joint moments during this time interval were also analyzed. Measures of gluteus medius activation, including latency, peak amplitude, and integrated signal, were recorded. Results: A small (<1°) increase in hip-abduction angle at initial contact and a small (<1°) decrease in knee-abduction (valgus) angle at 60 milliseconds after contact were observed in the postfatigue landing condition. No other kinematic changes were noted for the knee or hip at initial contact or at 60 milliseconds after initial contact. Peak external knee-adduction moment decreased 27% and peak hip adduction moment decreased 24% during the postfatigue landing condition. Gluteus medius activation was delayed after the protocol, but no difference in peak or integrated signal was seen during the landing trials. Conclusions: Changes observed during single-leg landings after hip-abductor fatigue were not generally considered unfavorable to the integrity of the anterior cruciate ligament. Further work may be

The flow field associated with a jet impinging onto a surface at an inclined angle is investigated using the image-based technologies of Temperature- and Pressure-Sensitive Paints and Particle Image Velocimetry. These diagnostics are used to produce two-dimensional measurements of temperature, Nusselt number, and pressure on the impingement surface and two-components of velocity above the surface. In the process of measuring Nusselt number a novel technique for determining the adiabatic wall temperature has been developed. This image-based technique was used to measure the adiabatic wall temperature on the impingement surface beneath both compressible and incompressible jets. The results of this investigation indicate that as a free jet impinges on a flat surface at an inclined angle the jet is turned by and spread laterally onto the impingement surface. The impingement angle of the jet is the dominant parameter in determining the rate of turning/spreading for the jet. Qualitatively, the structure of the half maximum pressure contour on the impingement surface is similar to an ellipse created by projecting the nozzle through the impingement surface. The center of the ellipse is located near the location of maximum pressure and the eccentricity is a function of the impingement angle. The width of the minor axis is just over one jet diameter. The point of maximum pressure, Nusselt number, and the stagnation point are each located upstream of the geometric impingement point, and this location is a strong function of impingement angle. The relative locations of the stagnation point, the point of maximum Nusselt number, the point of maximum pressure, and the geometric impingement point are identified and a simple correlation for the location of each of these points relative to the geometric impingement point is presented. Finally, the maximum value of both pressure and Nusselt number are found to be a function of impingement distance and impingement angle.

The method of plasty for the hip region sores, based on transposition of proximal part of m. tensor fascia latae in content of the flap, using her transsection between place of attachment to spina iliaca anterior superior and place of the main vascular pedicle entry into the muscle, was proposed, what permits to prevent vast mobilization of the muscle and to secure existing in normal conditions and formed in pathological conditions anas- tomoses between vascular net of the flap and surrounding tissues. The method proposed was successfully applied for plasty of the hip region sores of degrees III-IV in 2 patients. PMID:25985701

One of the most important issues in the modern total hip arthroplasty (THA) is the bearing surface. Extensive research on bearing surfaces is being conducted to seek an ideal bearing surface for THA. The ideal bearing surface for THA should have superior wear characteristics and should be durable, bio-inert, cost-effective, and easy to implant. However, bearing surfaces that are currently being implemented do not completely fulfill these requirements, especially for young individuals for whom implant longevity is paramount. Even though various new bearing surfaces have been investigated, research is still ongoing, and only short-term results have been reported from clinical trials. Future bearing surfaces can be developed in the following ways: (1) change in design, (2) further improvement of polyethylene, (3) surface modification of the metal, (4) improvement in the ceramic, and (5) use of alternative, new materials. One way to reduce wear and impingement in THA is to make changes in its design by using a large femoral head, a monobloc metal shell with preassembled ceramic liner, dual mobility cups, a combination of different bearing surfaces, etc. Polyethylene has improved over time with the development of highly crosslinked polyethylene. Further improvements can be made by reinforcing it with vitamin E or multiwalled carbon nanotubes and by performing a surface modification with a biomembrane. Surface modifications with titanium nitride or titanium niobium nitride are implemented to try to improve the metal bearings. The advance to the fourth generation ceramics has shown relatively promising results, even in young patients. Nevertheless, further improvement is required to reduce fragility and squeaking. Alternative materials like diamond coatings on surfaces, carbon based composite materials, oxidized zirconium, silicon nitride, and sapphire are being sought. However, long-term studies are necessary to confirm the efficacy of these surfaces after enhancements

One of the most important issues in the modern total hip arthroplasty (THA) is the bearing surface. Extensive research on bearing surfaces is being conducted to seek an ideal bearing surface for THA. The ideal bearing surface for THA should have superior wear characteristics and should be durable, bio-inert, cost-effective, and easy to implant. However, bearing surfaces that are currently being implemented do not completely fulfill these requirements, especially for young individuals for whom implant longevity is paramount. Even though various new bearing surfaces have been investigated, research is still ongoing, and only short-term results have been reported from clinical trials. Future bearing surfaces can be developed in the following ways: (1) change in design, (2) further improvement of polyethylene, (3) surface modification of the metal, (4) improvement in the ceramic, and (5) use of alternative, new materials. One way to reduce wear and impingement in THA is to make changes in its design by using a large femoral head, a monobloc metal shell with preassembled ceramic liner, dual mobility cups, a combination of different bearing surfaces, etc. Polyethylene has improved over time with the development of highly crosslinked polyethylene. Further improvements can be made by reinforcing it with vitamin E or multiwalled carbon nanotubes and by performing a surface modification with a biomembrane. Surface modifications with titanium nitride or titanium niobium nitride are implemented to try to improve the metal bearings. The advance to the fourth generation ceramics has shown relatively promising results, even in young patients. Nevertheless, further improvement is required to reduce fragility and squeaking. Alternative materials like diamond coatings on surfaces, carbon based composite materials, oxidized zirconium, silicon nitride, and sapphire are being sought. However, long-term studies are necessary to confirm the efficacy of these surfaces after enhancements

Traumatic hip dislocations are high-energy injuries that often result in considerable morbidity. Although appropriate management improves outcomes, associated hip pathology may complicate the recovery and lead to future disability and pain. Historically, open reduction has been the standard of care for treating hip dislocations that require surgical intervention. The use of hip arthroscopy to treat the sequelae and symptoms resulting from traumatic hip dislocations recently has increased, however. When used appropriately, hip arthroscopy is a safe, effective, and minimally invasive treatment option for intra-articular pathology secondary to traumatic hip dislocation. PMID:27007728

Introduction Anterior uveitis is rare, with an annual incidence of 12/100,000 population, although it is more common in Finland (annual incidence of 23/100,000), probably because of genetic factors, such as high frequency of HLA–B27 in the population. It is often self-limiting, but can, in some cases, lead to complications such as posterior synechiae, cataract, glaucoma, and chronic uveitis. Methods and outcomes We conducted a systematic review and aimed to answer the following clinical question: What are the effects of anti-inflammatory eye drops on acute anterior uveitis? We searched: Medline, Embase, The Cochrane Library and other important databases up to November 2009 (Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). Results We found six systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. Conclusions In this systematic review we present information relating to the effectiveness and safety of the following interventions: corticosteroids, mydriatics, and non-steroidal anti-inflammatory drug eye drops. PMID:21736765

Objective To investigate the relationship between the q-angle and anterior knee pain severity, functional capacity, dynamic knee valgus and hip abductor torque in women with patellofemoral pain syndrome (PFPS). Methods This study included 22 women with PFPS. The q-angle was assessed using goniometry: the participants were positioned in dorsal decubitus with the knee and hip extended, and the hip and foot in neutral rotation. Anterior knee pain severity was assessed using a visual analog scale, and functional capacity was assessed using the anterior knee pain scale. Dynamic valgus was evaluated using the frontal plane projection angle (FPPA) of the knee, which was recorded using a digital camera during step down, and hip abductor peak torque was recorded using a handheld dynamometer. Results The q-angle did not present any significant correlation with severity of knee pain (r = −0.29; p = 0.19), functional capacity (r = −0.08; p = 0.72), FPPA (r = −0.28; p = 0.19) or isometric peak torque of the abductor muscles (r = −0.21; p = 0.35). Conclusion The q-angle did not present any relationship with pain intensity, functional capacity, FPPA, or hip abductor peak torque in the patients with PFPS. PMID:27069887

Multiple factors regarding surgical procedures and patient selection affect hospital staffing needs as well as hospital revenues. In order to better understand the potential impact on hospitals that hip arthroplasty device selection (standard total hip arthroplasty vs. resurfacing) creates, a review of all primary hip arthroplasties performed at one institution was designed to identify factors that impacted hospital staffing needs and revenue generation. All primary hip arthroplasties undertaken over three fiscal years (2008 to 2010) were reviewed, utilizing only hospital business office data and medical records data that had been previously extracted prior for billing purposes. Analysis confirmed differing demographics for two hip arthroplasty populations, with the resurfacing patients (compared to the conventional total hip arthroplasty population) consisting of younger patients (mean age, 50 vs. 61 years), who were more often male (75% vs. 45%), were more likely to have osteoarthritis as their primary diagnosis (83 vs. 67%) and were more often covered by managed care or commercial insurance (83 vs. 34%). They also had shorter hospital stays (mean length of stay, 2.3 vs. 4.1 days) and consequently provided a more favorable financial revenue stream to the hospital on a per patient basis. Several trends appeared during the study periods. There was a steady increase in all procedures in all groups except for the resurfacings, which decreased 26% in males and 53% in females between 2009 and 2010. Differences were observed in the demographics of patients presenting for resurfacing, compared to those presenting for conventional total hip arthroplasty. In addition to the revenue stream considerations, institutions undertaking a resurfacing program must commit the resources and planning in order to rehabilitate these patients more expeditiously than is usually required with conventional hip arthroplasty patients. PMID:22035493

Aim: To assess similarities and differences in patient-related characteristics before and after surgery for painful disabling hip osteoarthritis among elderly subgroups with and without a trauma history. Method: First, a cohort of 1000 hospitalized patients were assessed for trends in: perceived duration of the condition, pain intensity, functional performance ability, walking distance, body mass, and comorbidity characteristics among other factors. Then, the most salient of these patient-related characteristics were compared between 42 cases of hip osteoarthritis without a trauma history and 42 cases with a trauma history matched for age and gender, using medical records and standard data recording and analysis procedures. Results: Hip osteoarthritis cases with a prior hip fracture history had a longer duration of disability, and were more impaired functionally before surgery (p < 0.05) than those with no such history. They also had lower leg muscle strength and used more assistive devices. Conclusion: Patients undergoing hip replacement surgery for painful hip osteoarthritis who have a hip fracture history are likely to be more impaired and disabled than those with no such history. PMID:19478931

The heat transfer performance of swirling impinging jets was experimentally investigated, and the flow fields were visualized for a jet diameter, d{sub j} = 12.7 mm and swirl angles, {theta} = 15{degree}, 30{degree}, and 45{degree}. Other experimental parameters included Reynolds number, Re = 3,620--17,600, vertical jet spacing, h = 12.7--76.2 mm, and radial distance from the stagnation point, r = 0--65 mm. The results showed significant enhancement in the heat transfer coefficient, both with respect to radial uniformity and local values, compared to a circular straight impinging jet of the same dimensions at the same test conditions. The flow field visualizations confirmed the measured enhancement in the heat transfer coefficient for the swirling jets as well as the radial distribution of local Nusselt number.

The Orbiter RCS flowfield is modeled in the free molecular region and an impingement analysis is performed to characterize on-orbit plume interactions with nearby bodies, such as the SPAS-01 satellite. The flow in the far field is treated with a source flow model at any point 40 ft from the nozzle. Impingement is calculated according to Newtonian impact theory. The flow density in the far field is expressed in terms of a conservation of energy equation, with account taken of the expansion of the gas, cooling, and the angular distribution. The SPAS-01 platform gathered data at eight different positions around the Orbiter to test the model predictions. Excellent agreement was obtained in predictions of the torque and rotation rate induced on the SPAS by firing the thrusters.

In some gas turbine engine designs cooling air jets are directed at the rotating disk in an atempt to enhance the convection coefficients and reduce the amount of gas flow required for cooling. The jet-impingement scheme is particularly attractive for achieving intense cooling at a specific radial location, such as the blade attachment region. In earlier single-jet studies, the interaction between an impinging jet and rotating disk has been found to involve a flow regime transition. The present study extends the previously acquired data base with new results from both heat-transfer and flow-visualization testing, including effects of hub size, jet travel distance, and the number of jets. Results include a superposition scheme for predicting heat transfer for multiple jets and a criterion for the minimum amount of flow required through each jet nozzle to assure enhancement of the disk convection.

This paper describes the atomization performance of a newly designed atomizer with internal impinging mechanisms inside the atomizer. The spray drop size distribution was measured by a Malvern RT-Sizer. Results show that the Sauter mean diameter below 10µm has been achieved with GLR of 0.14. The minimum mean drop size can be lowered to 4.0µm under a test condition of the liquid pressure and gas pressure of 2.5bar and 3.5bar, respectively. This test suggests that extra fine atomization on the liquid phase can be achieved under low pressure conditions using this particular atomizer. Such performance cannot be easily achieved with the conventional nozzle design. Results also show that better atomization performance can be achieved by increasing the internal impinging angle and the orifice diameter. An empirical formula of SMD, in terms of operating conditions and nozzle length scale is also presented in this paper.

Heat transport in impinging jets makes a part of many experimental and numerical studies because some similarities can be identified between a pure impingement jet and industrial processes like, for example, the heat transfer at the bottom of an agitated vessel. In this paper, experimental results based on measuring the response to heat flux oscillations applied to the heat transfer surface are compared with CFD simulations. The computational cost of a LES-based approach is usually too high therefore a comparison with less computationally expensive RANS-based turbulence models is made in this paper and a possible improvement of implementing an anisotropic explicit algebraic model for the turbulent heat flux model is evaluated.

An experimental study was performed to characterize the boiling heat transfer of impinging circular submerged jets on simulated microelectronic chips with a nominal area of 5 mm × 5 mm. The heat transfer modes included natural convection, partially developed nucleate boiling, fully developed nucleate boiling and critical heat flux. The study included the effects of jet parameters and fluid subcooling on the nucleate boiling. The results showed that the nucleate boiling data varied only with fluid subcooling regardless of jet parameters and that both the pool and impingement nucleate boiling curves at the same subcooling condition were well correlated. The high heat flux portions of the boiling curves with jet exit velocities greater than 10 m/s were corrected for the elevated saturation temperature. A new expression was developed with an interpolation method to construct the partially developed nucleate boiling curve.

The present invention provides a method for producing an anterior cruciate ligament ex vivo. The method comprises seeding pluripotent stem cells in a three dimensional matrix, anchoring the seeded matrix by attachment to two anchors, and culturing the cells within the matrix under conditions appropriate for cell growth and regeneration, while subjecting the matrix to one or more mechanical forces via movement of one or both of the attached anchors. Bone marrow stromal cells are preferably used as the pluripotent cells in the method. Suitable matrix materials are materials to which cells can adhere, such as a gel made from collagen type I. Suitable anchor materials are materials to which the matrix can attach, such as Goinopra coral and also demineralized bone. Optimally, the mechanical forces to which the matrix is subjected mimic mechanical stimuli experienced by an anterior cruciate ligament in vivo. This is accomplished by delivering the appropriate combination of tension, compression, torsion, and shear, to the matrix. The bioengineered ligament which is produced by this method is characterized by a cellular orientation and/or matrix crimp pattern in the direction of the applied mechanical forces, and also by the production of collagen type I, collagen type III, and fibronectin proteins along the axis of mechanical load produced by the mechanical forces. Optimally, the ligament produced has fiber bundles which are arranged into a helical organization. The method for producing an anterior cruciate ligament can be adapted to produce a wide range of tissue types ex vivo by adapting the anchor size and attachment sites to reflect the size of the specific type of tissue to be produced, and also adapting the specific combination of forces applied, to mimic the mechanical stimuli experienced in vivo by the specific type of tissue to be produced. The methods of the present invention can be further modified to incorporate other stimuli experienced in vivo by the

A unified power-law relationship between average erosion rate and cumulative erosion is presented. Extensive data analyses from venturi, magnetostriction (stationary and oscillating specimens), liquid drop, and jet impact devices appear to conform to this relation. A normalization technique using cavitation and liquid impingement erosion data is also presented to facilitate prediction. Attempts are made to understand the relationship between the coefficients in the power-law relationships and the material properties.

The origin of chronic pain after external ankle sprain is better known with arthroscopy's contribution. Chronic hypertrophic synovitis of the anterolateral ankle region is seemingly the cause, resulting in "anterolateral ankle impingement." But is partial synovectomy with fibrosis resection under arthroscopy always possible without any distraction? Are results affected? This retrospective study concerned only patients with soft tissue ankle impingement. All cases with bone and joint diseases were excluded. The final sample of 24 patients had a mean age of 35 years (21-54 years) and presented anterolateral mechanical pain associated with oedema following external ankle sprain. Medical and rehabilitative treatment was undertaken for more than 6 months before arthroscopy. Average time between trauma and arthroscopy was 21 months (5-60 months). Clinical examination revealed no ankle instability or laxity. Debridement with joint lavage was systematically performed under arthroscopy without any distraction. Average patient follow-up was 22 months (12-92 months). All patients had a good Kitaoka score, with 22 patients registering excellent results. There were no septic complications or algodystrophy. Two transient hypoesthesias were observed in the dorsal surface and lateral border of the foot with full postoperative recovery at 6 months. Distraction was never used and simple dorsiflexion was sufficient to perform arthroscopic debridement. In this study, anterolateral ankle impingement diagnosis was primarily clinical. Arthroscopic treatment yielded significant benefits on pain, oedema and resumption of sport activities. Arthroscopic treatment of anterolateral ankle impingements is thus possible with simple dorsiflexion and no distraction, resulting in a possible decrease in complication rates. Level of evidence Retrospective cohort study, Level IV. PMID:24220747

The impingement of a submerged, liquid jet onto a cell-covered surface allows assessing cell attachment on surfaces in a straightforward and quantitative manner and in real time, yielding valuable information on cell adhesion. However, this approach is insufficiently characterized for reliable and routine use. In this work, we both model and measure the shear stress exerted by the jet on the impingement surface in the micrometer-domain, and subsequently correlate this to jet-induced cell detachment. The measured and numerically calculated shear stress data are in good agreement with each other, and with previously published values. Real-time monitoring of the cell detachment reveals the creation of a circular cell-free area upon jet impingement, with two successive detachment regimes: 1), a dynamic regime, during which the cell-free area grows as a function of both the maximum shear stress exerted by the jet and the jet diameter; followed by 2), a stationary regime, with no further evolution of the cell-free area. For the latter regime, which is relevant for cell adhesion strength assessment, a relationship between the jet Reynolds number, the cell-free area, and the cell adhesion strength is proposed. To illustrate the capability of the technique, the adhesion strength of HeLa cervical cancer cells is determined ((34 ± 14) N/m2). Real-time visualization of cell detachment in the dynamic regime shows that cells detach either cell-by-cell or by collectively (for which intact parts of the monolayer detach as cell sheets). This process is dictated by the cell monolayer density, with a typical threshold of (1.8 ± 0.2) × 109 cells/m2, above which the collective behavior is mostly observed. The jet impingement method presents great promises for the field of tissue engineering, as the influence of both the shear stress and the surface characteristics on cell adhesion can be systematically studied. PMID:25564849

Local steroid injections are common for treatment of impingement syndrome. Corticosteroid injections methods are basically in two formats, blind or with image guidance. The aim of this study is to compare the effect of ultrasound-guided in comparison with blind corticosteroid injections in patients with impingement syndrome. This study is a randomized clinical trial study undertaken in patients with diagnosis of impingement syndrome done in Isfahan University of Medical Science clinics from February 2014 to February 2015. The number of all patients registered in the study is 48; and then 40 patients were allocated to either control group randomly which received blind steroid injection or case group that underwent ultrasound-guided steroid injection. The clinical symptoms were assessed using Shoulder Pain and Disability Index (SPADI) questionnaire, Visual Analogue Scale (VAS) and shoulder range of motion (ROM) using goniometer at baseline and six weeks after the injection. Data analysis revealed a significant difference in the mean of the VAS, SPADI and shoulder ROM in both groups 6 weeks after intervention (P < 0.05). Patients with ultrasound guided corticosteroid injection had statistically significant improvements in function and shoulder ROM (abduction, flexion) compared to blind injection group after 6 weeks (P<0.05). There was not significant differences in pain (VAS) and internal and external rotation between these two groups (p>0.05). Our findings suggest that US image guided can improve the shoulder function of patients with impingement syndrome, and thus can be considered in comprehensive care programs of these patients for fast speed of rehabilitation.

In order to gain a better insight into flow, vortical and turbulence structure and their correlation with the local heat transfer in impinging flows, we performed large-eddy simulations (LES) of a round normally impinging jet issuing from a long pipe at Reynolds number Re = 20000 at the orifice-to-plate distance H = 2D, where D is the jet-nozzle diameter. This configuration was chosen to match previous experiments in which several phenomena have been detected, but the underlying physics remained obscure because of limitations in the measuring techniques applied. The instantaneous velocity and temperature fields, generated by the LES, revealed interesting time and spatial dynamics of the vorticity and eddy structures and their imprints on the target wall, characterized by tilting and breaking of the edge ring vortices before impingement, flapping, precessing, splitting and pairing of the stagnation point/line, local unsteady separation and flow reversal at the onset of radial jet spreading, streaks pairing and branching in the near-wall region of the radial jets, and others. The LES data provided also a basis for plausible explanations of some of the experimentally detected statistically-averaged flow features such as double peaks in the Nusselt number and the negative production of turbulence energy in the stagnation region. The simulations, performed with an in-house unstructured finite-volume code T-FlowS, using second-order-accuracy discretization schemes for space and time and the dynamic subgrid-scale stress/flux model for unresolved motion, showed large sensitivity of the results to the grid resolution especially in the wall vicinity, suggesting care must be taken in interpreting LES results in impinging flows.

The cementless stem Excia (B. Braun, Melsungen, Germany) implant has a rectangular cross-sectional shape with back-and-forth flanges and a plasma-sprayed, dicalcium phosphate dihydrate coating from the middle to proximal portion to increase initial fixation and early bone formation. Here, the conformity of the Excia stem to the femoral canal morphology was three-dimensionally assessed using computed tomography. Forty-three patients (45 hips) were examined after primary total hip arthroplasty with a mean follow-up of 27 ± 3 months (range: 24–36 months). Spot welds occurred at zone 2 in 16 hips and at zone 6 in 24 hips, with 83% (20/24 hips) of those occurring within 3 months after surgery. First- (n = 12 hips), second- (n = 32), and third- (n = 1) degree stress shielding were observed. The stem was typically in contact with the cortical bone in the anterolateral mid-portion (100%) and posteromedial distal portions (85%). Stress shielding did not progress, even in cases where the stems were in contact with the distal portions. The anterior flange was in contact with the bone in all cases. The stability of the mid-lateral portion with the dicalcium phosphate dihydrate coating and the anterior flange may have inhibited the progression of stress shielding beyond the second degree. PMID:26881087

During pregnancy, the female body experiences structural changes, such as weight gain. As pregnancy advances, most of the additional mass is concentrated anteriorly on the lower trunk. The purpose of this study is to analyze kinematic and kinetic changes when load is added anteriorly to the trunk, simulating a physical change experienced during pregnancy. Twenty healthy females walked on a treadmill while wearing a custom made pseudo-pregnancy sac (1 kg) under 3 load conditions: sac-only condition, 10-lb condition (4.535 kg added anteriorly), and 20-lb condition (9.07 kg added anteriorly), used to simulate pregnancy in the second trimester and at full-term pregnancy, respectively. The increase in anterior mass resulted in kinematic changes at the knee, hip, pelvis, and trunk in the sagittal and frontal planes. In addition, ankle, knee, and hip joint moments normalized to baseline mass increased with increased load; however, these moments decreased when normalized to total mass. These kinematic and kinetic changes may suggest that women modify gait biomechanics to reduce the effect of added load. Furthermore, the increase in joint moments increases stress on the musculoskeletal system and may contribute to musculoskeletal pain. PMID:26958743

The objective of this study was to test if patients with unilateral hip osteoarthritis (OA) show greater muscle activity asymmetry between their affected and non-affected limbs than healthy controls between their left and right limbs. Seventeen patients with unilateral hip OA (7 females, 10 males) and 17 age-matched healthy controls (7 females, 10 males) participated in this study. Both groups performed instrumented gait analysis at comparable speeds. Muscle activity was recorded simultaneously for the tibialis anterior (TA), gastrocnemius medialis (GM), vastus lateralis (VL), semitendinosus (ST), tensor fasciae latae (TFL), and gluteus medius (GLM) muscles. In hip OA patients, EMG data showed greater activity of the TA muscle in the non-affected limb, and greater TFL muscle activity in the affected limb. Compared to healthy controls, greater asymmetries between paired limbs were observed for the TA and GM muscles. Finally, the TFL muscle of the affected limb contributed more to the total limb muscle activity than did the non-affected limb. The observed alterations in TA and GM muscle activity in hip OA patients may be due to the greater peak braking and peak vertical forces measured in the non-affected limb. Contrary to this, greater TLF muscle activity of the affected limb indicates the demands put on stabilizing the hip during stance phase. Further studies are necessary to test whether leg length discrepancy affects muscle activation alterations between the affected and non-affected limb in unilateral hip OA patients. PMID:26979904

Background Asymmetric bilateral hip dislocations are a rare injury pattern in which one hip dislocates posteriorly, and the contralateral hip dislocates anteriorly. We report a case of bilateral asymmetric hip dislocations and provide a comprehensive review of all available reports, identifying 104 total cases, which is 70 more than previously reported. Purpose To review and evaluate the total body of literature regarding bilateral asymmetric hip dislocations. Methods Comprehensive literature review and analysis of all reports of bilateral asymmetric hip dislocations with concurrent case report. Results and Conclusions Bilateral, asymmetric represent approximately 0.01%–0.02% of all joint dislocations. There has been a substantial increase in the number of case reports in the literature in the last 10 years. Males are more likely than females to incur this injury pattern and the most common mode of injury is motor vehicle accident Urgent closed reduction should be attempted in an efficient and safe manner to avoid potential complications, and open reduction should be considered in irreducible dislocations. Post reduction management should include stability assessment and CT to assess for associated injuries and intraarticular fragments; although no clear guidelines for post-reduction treatment emerged. Common complications include: nerve palsies, AVN and heterotopic ossification. PMID:26361448

Experiments on the aeroacoustics of an under-expanded supersonic jet impinging on a flat plate are presented and thoroughly discussed. A wide range of nozzle pressure ratios and of nozzle-to-plate distances has been analyzed with particular attention to the behavior of the discrete component of the noise. The investigation has been carried out by means of acoustic, particle image velocimetry and wall pressure measurements. The analysis of the relationship between the acoustic data and the fluid dynamic fields allows to examine the different source mechanisms of the discrete component of the noise and to evaluate the link between the jet flow structure and the acoustic tone features. Specifically, two ranges of nozzle pressure ratio have been observed showing different acoustic behaviors, characterized by distinct mechanisms of discrete noise generation. These regions are separated by a range of nozzle pressure ratios where impinging tones are not observed. The present experimental data extend previously published results, improving the analysis of the connection between fluid dynamic and acoustic fields and leading to a better comprehension of the impinging tone source mechanisms.

The behavior of impinging single synthetic jet and twin circular synthetic jets in phase opposition is experimentally investigated by using Particle Image Velocimetry (PIV) at Reynolds and Strouhal numbers equal to 5100 and 0.024, respectively. Different inter-axes distances for the twin configuration and several nozzle-to-plate distances have been investigated. The time-averaged behavior of the all velocity components are reported and discussed. Their distributions, near the impinging plate, are described for both the synthetic jet configurations and for all the nozzle-to-plate distances. At low nozzle-to-plate distance (H/D <4) the axial velocity profile near the impinging plate shows a double peak with a minimum on the jet axis. Instead, at high nozzle-to-plate distance (H/D >6), the axial velocity profile is bell-shaped. This is ascribed to the adverse pressure gradient strength and the potential core-like region extension. Indeed, the turbulence distribution shows a region characterized by low values, resembling the potential core region of continuous jets. Comparing the two synthetic jet configurations, a higher centerline velocity and a smaller jet width have been found for the twin case.

The chronic ankle pain is a very frequent clinical problem, which is often characterized by a painful mechanical limitation of full-range ankle movement. A large amount of causes are involved in its pathogenesis, but the most common forms are secondary to an osseous or soft tissue abnormality. Especially for professional athletes, impingement lesions are the most important causes of chronic pain; however, this symptomatology can also affect ordinary people, mostly in those who work in environments that cause severe mechanical stress on the joints. This group of pathologies is characterized by a joint conflict secondary to an abnormal contact among bone surfaces or between bones and soft tissues. Diagnosis is mainly clinic and secondly supported by imaging in order to localize the critical area of impingement and determine the organic cause responsible for the joint conflict. Treatments for different forms of impingement are similar. Usually, the first step is a conservative approach (rest, physiotherapy, ankle bracing, shoe modification and local injection of corticosteroids), and only in case of unsuccessful response, the second step is the operative treatment with open and arthroscopic techniques. The aim of the study is to describe different MR imaging patterns, comparing our data with those reported in the literature, in order to identify the best accurate diagnostic protocol. PMID:23949936

Objective: To describe the pain and functional improvements of a patient with posterior ankle impingement following a treatment plan incorporating soft tissue therapy, chiropractic adjustment and a progressive rehabilitation program. Clinical Features: A 37-year- old male presented with posterolateral ankle pain exacerbated by plantar flexion two weeks after sustaining an inversion ankle sprain. Oedema was present and the patient was describing a sensation of instability while walking. The initial diagnosis of lateral ankle sprain was found to be complicated by a posterior ankle impingement caused by a tenosynovitis of the flexor hallucis longus sheath suspected during the physical examination and confirmed by MRI. Intervention and Outcome: The patient was treated over a 14-week period. Soft tissue therapy, a rehabilitation program and cortisone injection were used to treat this condition. A precise description of the rehabilitation program that contains open kinetic chain, closed kinetic chain, proprioception, and conditioning exercises prescribed to the patient is given. After the treatment plan, the patient returned to play pain free and had no daily living restrictions. Summary: A protocol including rest, soft tissue therapy, open and closed kinetic chain exercises, sport-specific exercises and cortisone injection appeared to facilitate complete recovery of this patient’s posterior ankle impingement. PMID:27385836

An experimental investigation of heat transfer from a single round free jet, impinging normally on a flat plate is described. Flow at the exit plane of the jet is fully developed and the total temperature of the jet is equal to the ambient temperature. Infrared measurements lead to the characterization of the local and averaged heat transfer coefficients and Nusselt numbers over the impingement plate. The adiabatic wall temperature is introduced as the reference temperature for heat transfer coefficient calculation. Various nozzle diameters from 3 mm to 15 mm are used to make the injection Mach number M vary whereas the Reynolds number Re is kept constant. Thus the Mach number influence on jet impingement heat transfer can be directly evaluated. Experiments have been carried out for 4 nozzle diameters, for 3 different nozzle-to-target distances, with Reynolds number ranging from 7200 to 71,500 and Mach number from 0.02 to 0.69. A correlation is obtained from the data for the average Nusselt number. PMID:11460655

Impingement of capillary jet on a surface is important for applications like heat transfer, or for liquid manipulation in bio-microfluidic devices. Using wettability engineered surfaces, we demonstrate pump-less and directional transport of capillary jet on a flat surface. Spatial contrast of surface energy and a wedge-shape geometry of the wettability confined track on the substrate facilitate formation of instantaneous spherical bulges upon jet impingement; these bulges are further transported along the superhydrophilic tracks due to Laplace pressure gradient. Critical condition warranted for formation of liquid bulge along the varying width of the superhydrophilic track is calculated analytically and verified experimentally. The work throws light on novel fluid phenomena of unidirectional jet impingement on wettability confined surfaces and provides a platform for innovative liquid manipulation technique for further application. By varying the geometry and wettability contrast on the surface, one can achieve volume flow rates of ~ O(100 μL/sec) and directionally guided transport of the jet liquid, pumplessly at speeds of ~ O(10cm/sec).

The presented paper shows the possibility of using holographic interferometry and hot-wire anemometry in the research of heat transfer from impingement pulsatile flow. The intensity of heat transfer in the case of impingement flow is often measured with glue-on heat flux sensors, or by indirect methods such as naphthalene sublimation. All these methods have a response time too long for measuring instant values of the heat transfer coefficient on a surface cooled/heated by impingement pulsatile flow. This shortcoming should be overcome by using CTA glue-on probes or, preferably, by using optical methods such as holographic interferometry. It is necessary to employ a special holographic setup with double sensitivity instead of the commonly used Mach-Zehnder type of holographic interferometer in order to attain the parameters sufficient for the studied case. This setup is not light efficient like the Mach-Zehnder type but has double sensitivity. The results from the holographic interferometry experiments will be compared with the temperature field achieved by methods of hot-wire anemometry.

In turbulent liquid jet impingement, a spray of droplets often breaks off of the liquid layer formed on the target. This splattering of liquid alters the efficiencies of jet impingement heat transfer processes and chemical containment safety devices, and leads to problems of aerosol formation in jet impingement cleaning processes. In this paper, the authors present a more complete study of splattering and improved correlations that extend and supersede the previous reports on this topic. The authors report experimental results on the amount of splattering for jets of water, isopropanol-water solutions, and soap-water mixtures. Jets were produced by straight tube nozzles of diameter 0.8--5.8 mm, with fully developed turbulent pipe-flow upstream of the nozzle exist. These experiments cover Weber numbers between 130--31,000, Reynolds numbers between 2,700--98,000, and nozzle-to-target separations of 0.2 [<=]l/d[<=]125. Splattering of up to 75 percent of the incoming jet liquid is observed. The results show that only the Weber number and l/d affect the fraction of jet liquid splattered. The presence of surfactants does not alter the splattering. A new correlation for the onset condition for splattering is given. In addition, the authors establish the range of applicability of the model of Lienhard et al. and the authors provide a more accurate set of coefficients for their correlation.

High-velocity oxygen/air fuel (HVO/AF) WC-17Co and WC-10Co4Cr coatings exhibit great potential in the replacement of electrolytic hard chrome (EHC) plating, and comprehensive properties of such coatings should be superior to those of electrolytic hard chrome plating. The impingement resistance of HVAF WC-based coatings sprayed on 300M ultrahigh-strength steel was studied in this paper. As an important property index, the fracture toughness of HVAF WC-based coatings was measured using the microindentation method at loads of 9.8, 19.6, 24.5, 29.4, and 49.0 N, respectively. The cracks resulting from stress concentration in the microindentation were analyzed. The impingement resistance for two HVAF WC coatings and EHC was evaluated according to the ASTM D 3170 standard, and steel ball free-fall experiment was performed at the height of 0.61, 1.52, 1.83, 2.36, and 2.59 m, respectively. The cracks caused by both impingements were analyzed using scanning electron microscopy (SEM) and optical microscopy (OM) in comparison with the cracks in microindentation test.

The Constellation Project's planned return to the moon requires numerous landings at the same site. Since the top few centimeters are loosely packed regolith, plume impingement from the Lander ejects the granular material at high velocities. Much work is needed to understand the physics of plume impingement during landing in order to protect hardware surrounding the landing sites. While mostly qualitative in nature, the Apollo Lunar Module landing videos can provide a wealth of quantitative information using modem photogrammetry techniques. The authors have used the digitized videos to quantify plume impingement effects of the landing exhaust on the lunar surface. The dust ejection angle from the plume is estimated at 1-3 degrees. The lofted particle density is estimated at 10(exp 8)- 10(exp 13) particles per cubic meter. Additionally, evidence for ejection of large 10-15 cm sized objects and a dependence of ejection angle on thrust are presented. Further work is ongoing to continue quantitative analysis of the landing videos.

Spray cooling has high potential in thermal management and life support systems by overcoming the deleterious effect of microgravity upon two-phase heat transfer. In particular spray cooling offers several advantages in heat flux removal that include the following: 1. By maintaining a wetted surface, spray droplets impinge upon a thin fluid film rather than a dry solid surface 2. Most heat transfer surfaces will not be smooth but rough. Roughness can enhance conductive cooling, aid liquid removal by flow channeling. 3. Spray momentum can be used to a) substitute for gravity delivering fluid to the surface, b) prevent local dryout and potential thermal runaway and c) facilitate liquid and vapor removal. Yet high momentum results in high We and Re numbers characterizing the individual spray droplets. Beyond an impingement threshold, droplets splash rather than spread. Heat flux declines and spray cooling efficiency can markedly decrease. Accordingly we are investigating droplet impingement upon a) dry solid surfaces, b) fluid films, c) rough surfaces and determining splashing thresholds and relationships for both dry surfaces and those covered by fluid films. We are presently developing engineering correlations delineating the boundary between splashing and non-splashing regions.

More than 100000 hip replacements have been performed in Finland. In the hip replacement operations performed due to osteoarthritis, the artificial joint surfaces are made of metal, plastic or ceramics. Pseudotumors associated with metal-on-metal (MoM) sliding surfaces have received worldwide attention. Soft issue lesions, not always symptomatic, may develop around the joint replacements. These may even require joint revision surgery. PMID:26237883

Recent years have witnessed a growing number of people practising sports both at professional and amateur level. This trend led to a progressive rise in the incidence and prevalence of acute and chronic hip damage. The treatment of hip disease in subjects practising sports is a major challenge for the orthopaedic surgeon. The evaluation of patients, in particular those of young age with high functional demands, is inevitably complex and should be performed with a multidisciplinary approach; from a surgical point of view, it is essential to carefully assess whether the indication is towards conservative surgery or hip replacement surgery. The advent of arthroscopic surgery in recent years has allowed us to improve our knowledge of hip joint diseases, such as femoroacetabular impingement that is typical of sports and overuse activity. A correct and early diagnosis of the disease can direct the patient promptly to a conservative surgical treatment that could reduce the progression of degenerative pathology. However, when the joint is permanently damaged, the only reliable solution remains prosthetic surgery, leading to a series of issues that the orthopaedic surgeon should be able to master, leading to a thoughtful decision on, for example, which implant to use, which biomaterials, which surgical approach or which sport to practise after surgery. This supplement contains selected contributions stemming from the work performed by internationally recognised experts in the field and presented during the 1st European Hip Sport Meeting held in Bologna on May 19th, 20th, 2016 that we had the honour to co-chair. We hope that these contributions will help the orthopaedic surgeon, the sports physician and physiotherapist in their day-to-day practice, and will help in fulfilling our ultimate aim to improve the knowledge of the hip pathology related to sports and overuse activities. PMID:27174057

The objective of this study was to describe the footprint location of the iliopsoas tendon on the lesser trochanter to clarify the surgical implications of the lesser trochanterplasty for treating ischiofemoral impingement. Ten non-matched, fresh-frozen, cadaveric hemipelvis specimens (average age, 62.4 years; range, 48–84 years; 7 male and 3 female) were included. Registered measures included bony parameters of the lesser trochanter (lesser trochanteric area, distances from the tip to the base in a coordinate system, height and area) and tendinous iliopsoas footprint descriptions (areas and detailed location). The mean height of the lesser trochanter was 13.1 (SD ± 1.8) mm, with female having a smaller lesser trochanter on average (11.3, SD ± 2.0). A double tendinous footprint was found in 7 (70%) specimens. The average area of the single- and double-footprint was 211.2 mm2 and 187.9 mm2, respectively. An anterior cortical area with no tendinous insertion on the anterior aspect of lesser trochanter was present in all specimens and measured 4.9 mm (SD ± 0.6) on average. The mean ratio between the bald anterior wall and the lesser trochanter height was 38% (SD ± 0.05). The iliopsoas tendon footprint is double (psoas and iliacus) in most cases and is located on the anteromedial tip of the lesser trochanter. A bald anterior wall on the bottom of the lesser trochanter indicates that a partial or total lesser trochanterplasty for increasing the ischiofemoral space without detaching partially or entirely the iliopsoas tendon is improbable. PMID:27011863

The term “developmental dysplasia of the hip” (DDH) includes a wide spectrum of abnormalities that affect the hip during its growth, ranging from dysplasia to joint dislocation and going through different degrees of coxofemoral subluxation. The incidence of DDH is variable, and depends on a number of factors, including geographical location. Approximately one in 1,000 newborn infants may present hip dislocation and around 10 in 1,000 present hip instability. Brazil has an incidence of five per 1,000 in terms of findings of a positive Ortolani sign, which is the early clinical sign for detecting the disorder. The risk factors for DDH include: female sex, white skin color, primiparity, young mother, breech presentation at birth, family history, oligohydramnios, newborns with greater weight and height, and deformities of the feet or spine. Hip examinations should be routine for newborns, and should be emphasized in maternity units. Among newborns and infants, the diagnosis of DDH is preeminently clinical and is made using the Ortolani and Barlow maneuvers. Conventional radiography is of limited value for confirming the diagnosis of DDH among newborns, and ultrasound of the hip is the ideal examination. The treatment of DDH is challenging, both for pediatric orthopedists and for general practitioners. The objectives of the treatment include diagnosis as early as possible, joint reduction and stabilization of the hip in a secure position. Classically, treatment options are divided according to different age groups, at the time of diagnosis. PMID:27022528

Orthopedic surgery can alleviate the hip flexion, adduction, and medial rotation deformities of the hip and improve the function and appearance of gait. To accomplish this, however, careful examination and prudence in the operative procedure to avoid overdoing and overcorrecting are important. Orthopedic surgery can prevent subluxation and dislocation of the hip before the age of seven years, and consequently repetitive radiographic examinations of the hip in children who have spastic paralysis of the hip musculature should be a routine procedure. Subluxation and dislocation of the hip, when established, can be successfully treated with orthopedic surgical procedures. Physicians must keep in mind that the spastic paralysis of cerebral palsy originates in the brain, and therefore the spasticity cannot be eliminated. The best that can be done is to weaken or remove some muscles as deforming forces and to achieve compromises for continued function. The goal should be optimal independence for the child and adolescent during development, and freedom from pain with deteriorating function due to degenerative arthritis in the adult. PMID:7360505

We previously reported the five-to-six-year results of the use of third-generation alumina-on-alumina bearings in a consecutive series of 100 primary cementless total hip arthroplasties. This report presents the longer-term outcomes of these same bearings, at a minimum of ten years postoperatively. Eighty-six of eighty-eight hips available for the study retained the original bearings at the time of the latest follow-up. Thirteen hips were associated with noise, and six hips demonstrated fretting of the femoral neck on radiographs. Two hips required a change of the bearings because of a ceramic head fracture. The ten-year survival rate of the alumina-on-alumina total hip prostheses, with revision of any implant for any reason as the end point, was 99.0%. On the basis of those results, we concluded that the rate of survival of primary cementless total hip prostheses with third-generation alumina-on-alumina bearings is excellent at ten years. However, the risk of ceramic fracture, noise, and impingement between the metal neck and the ceramic liner should be a concern to surgeons, and patients should be informed of these risks before surgery. PMID:20660234

The non-syndromic anterior cervical hypertrichosis (OMIM N° 600457) is a genetic disorder characterized by a patch of hair at the level of the laryngeal prominence. We present a 12-year-old boy with anterior cervical hypertrichosis and mild generalized hypertrichosis. He has no neurological, ophthalmological or skeletal anomalies. The clinical follow up is 10 years. PMID:27606653

The symptoms of osteoarthritis vary widely from patient to patient, depending especially on the localization on the disease. There is a poor correlation between radiological involvement and pain. In general, symptom onset is gradual and symptoms increase slowly but progressively. The most commonly affected joints are the knees, hips, hands, and spine. The main signs and symptoms are pain, stiffness, joint deformity, and crepitus. Pain is mechanical and its causes are multifactorial; in the initial phases, pain usually manifests in self-limiting episodes but may subsequently be almost constant. The criteria of the American college of Rheumatology for the classification of osteoarthritis of the knee, hip and hands are an aid to classification and standardization but are not useful for diagnosis. Hip osteoarthritis usually produces inguinal pain in the internal and anterior sections of the muscle extending to the knee and, with progression, tends to limit mobility. Knee osteoarthritis is more frequent in women and is usually associated with hand osteoarthritis and obesity. In hand osteoarthritis, the most commonly affected joints are the distal interphalangeal joints, followed by the proximal interphalangeal joints and the trapeziometacarpal joints; the development of Heberden and Bouchard nodes is common; involvement of the trapeziometacarpal joint is called rhizarthrosis and is one of the forms of osteoarthritis that produces the greatest limitation on hand function. Osteoarthritis of the spine affects the facet joints and the vertebral bodies. Other, less frequent, localizations are the foot, elbow and shoulder, which are generally secondary forms of osteoarthritis. PMID:24467955

A mathematic model of the hip capsule and lower extremity musculature was utilized to predict the forces present in the hip ligaments during locomotion. The results demonstrate principles and trends (rather than absolute results) in hip mechanics, the details of which are affected by the associated modeling assumptions. The active stretching of a hip joint capsule tightened by scarring or surgical transfer may appreciably increase the hip contact force. Capsular elements that prevent hip flexion and adduction play a major role in hip contact force exaggeration during common activities. The positive effect of maintaining the hip capsule to reduce total hip component dislocation contrasts with the potential negative effects of restricting joint motion and increasing the joint contact force. Increased joint loading due to capsular restriction may contribute to prosthetic component loosening. PMID:6641064

Background: With the evolution of body contouring, few innovative alternatives have been developed for cosmetic treatment in the hip area. Methods: A multicenter controlled study was conducted, including a prior review of the literature regarding the hip area. Dissections were performed on 4 male cadavers, outlining the “musculoaponeurotic area of the hip.” The area was subdivided into anterior and posterior surfaces. A clinical study was conducted in 79 patients, obtaining a scale by using the most prominent points on the sides of both thighs as the main reference. With the lines marked on photographs and the measurements, a “clinicophotographic scaling system” was designed. Results: The anterior surface corresponds to the tensor fasciae latae and its tendon as well as to the aponeurosis of the gluteus medius. The posterior surface corresponds with the iliotibial tract and the tendon insertions of the gluteus maximus. The average dimensions of the cadaver “musculoaponeurotic area of the hip” are as follows: length, 17.5 cm, and width, 11.5 cm. Using the “clinicophotographic scaling system,” the dimensions are as follows: length, 14.9 cm, and width, 10.3 cm. Conclusions: The “musculoaponeurotic area of the hip” was defined involving muscles, tendons, aponeurosis, fascia, subcutaneous cellular tissue, and skin. The borders were established using important anatomical points that determine the length and width of the area. The “clinicophotographic scaling system” was used to clinically calculate the length and width of the area. By examination and palpation, the borders and dimensions of this area could be determined. PMID:26180724

After the low friction arthroplasty by John Charnley was no longer confined to specialized hospitals but commonplace in the general orthopedic practice, the issue remained how to most optimally reach the hip. The names of the authors of these approaches remain in a lot of cases connected to the approach. By evaluating the original articles in which the approaches are described we ascertain the original description and technique. By various sources we obtained the (short) biography of the people whose name is connected to the approach. Our research covers the biographies of colleagues Smith-Petersen, Watson-Jones, Hardinge, Charnley, Moore and Ludloff. The eponymous approaches are shown and described after the short biography on each individual. This study shows that without the work of our colleagues we cannot proceed in our profession. An understanding and knowledge of the people who dedicated themselves to developing the orthopedic surgery to the high standard it has today is the least honour we should give them. PMID:27139185

Dynamic hip kinematics during weight-bearing activities were analyzed for six healthy subjects. Continuous X-ray images of gait, chair-rising, squatting, and twisting were taken using a flat panel X-ray detector. Digitally reconstructed radiographic images were used for 3D-to-2D model-to-image registration technique. The root-mean-square errors associated with tracking the pelvis and femur were less than 0.3 mm and 0.3° for translations and rotations. For gait, chair-rising, and squatting, the maximum hip flexion angles averaged 29.6°, 81.3°, and 102.4°, respectively. The pelvis was tilted anteriorly around 4.4° on average during full gait cycle. For chair-rising and squatting, the maximum absolute value of anterior/posterior pelvic tilt averaged 12.4°/11.7° and 10.7°/10.8°, respectively. Hip flexion peaked on the way of movement due to further anterior pelvic tilt during both chair-rising and squatting. For twisting, the maximum absolute value of hip internal/external rotation averaged 29.2°/30.7°. This study revealed activity dependent kinematics of healthy hip joints with coordinated pelvic and femoral dynamic movements. Kinematics' data during activities of daily living may provide important insight as to the evaluating kinematics of pathological and reconstructed hips. PMID:25506056

The primary purpose of this review article is to discuss the role of diagnostic, corticosteroid, hyaluronic acid (HA) and platelet rich plasma (PRP) in the treatment of osteoarthritis (OA) and femoroacetabular impingement (FIA). These treatments play an important biological role in the non-operative management of these conditions. Two independent reviewers performed an search of PubMed for articles that contained at least one of the following search terms pertaining to intra-articular hip injection—local anaesthetic, diagnostic, ultrasound, fluoroscopic, image guided, corticosteroid, HA, PRP, OA, labral tears and FAI. Seventy-two full text articles were suitable for inclusion. There were 18 articles addressing the efficacy of diagnostic intra-articular hip injections. With respect to efficacy in OA there were 25 articles pertaining to efficacy of corticosteroid, 22 of HA and 4 of PRP. There were three articles addressing the efficacy of biologics in FAI. Diagnostic intra-articular hip injections are sensitive and specific for differentiating between intra-articular, extra-articular and spinal causes of hip symptoms. Ultrasound and fluoroscopy improves the precision of intra-articular positioning of diagnostic injections. Corticosteroids are more effective than HA and PRP in alleviating pain from hip OA. A higher dose of corticosteroids produces a longer benefit but volume of injection has no significant effect. Intra-articular corticosteroids do not increase infection rates of subsequent arthroplasty. There is currently limited evidence to warrant the routine use of therapeutic injections in the management of labral tears and FIA. PMID:27026814

The primary purpose of this review article is to discuss the role of diagnostic, corticosteroid, hyaluronic acid (HA) and platelet rich plasma (PRP) in the treatment of osteoarthritis (OA) and femoroacetabular impingement (FIA). These treatments play an important biological role in the non-operative management of these conditions. Two independent reviewers performed an search of PubMed for articles that contained at least one of the following search terms pertaining to intra-articular hip injection-local anaesthetic, diagnostic, ultrasound, fluoroscopic, image guided, corticosteroid, HA, PRP, OA, labral tears and FAI. Seventy-two full text articles were suitable for inclusion. There were 18 articles addressing the efficacy of diagnostic intra-articular hip injections. With respect to efficacy in OA there were 25 articles pertaining to efficacy of corticosteroid, 22 of HA and 4 of PRP. There were three articles addressing the efficacy of biologics in FAI. Diagnostic intra-articular hip injections are sensitive and specific for differentiating between intra-articular, extra-articular and spinal causes of hip symptoms. Ultrasound and fluoroscopy improves the precision of intra-articular positioning of diagnostic injections. Corticosteroids are more effective than HA and PRP in alleviating pain from hip OA. A higher dose of corticosteroids produces a longer benefit but volume of injection has no significant effect. Intra-articular corticosteroids do not increase infection rates of subsequent arthroplasty. There is currently limited evidence to warrant the routine use of therapeutic injections in the management of labral tears and FIA. PMID:27026814

This study compared the femoral stem revision and loosening rates in primary total hip arthroplasty between 2 different approaches and stem designs. Recent reports comparing the direct anterior approach with either the posterior or lateral approach showed that patients undergoing the direct anterior approach have less pain and an accelerated functional recovery in the early postoperative period. After converting to an anterior approach, the authors observed an increased rate of femoral stem revision. From 2003 to 2009, a posterior or lateral approach was used to insert 514 stems of 2 designs. These cases included the use of an extensively coated cobalt-chrome stem (n=232) or a straight, dual-tapered, proximally porous-coated titanium stem (n=282). In the following years, from 2009 to 2012, 594 short, proximally coated, titanium tapered-wedge stems were inserted through a direct anterior approach. The revision rates of femoral stems inserted through a posterior approach or a lateral approach were compared with those inserted via a direct anterior approach. No stem revisions occurred in the posterior approach group or the lateral approach group, and 5 stems were revised in the anterior approach group for periprosthetic fracture or aseptic loosening (0.8%). Significantly more stem revisions occurred after the use of the new stem design and a direct anterior approach (P=.04). PMID:26726989

Hip fractures are associated with significant mortality and morbidity for the patients, more dependent residual status, and increased socio-economic cost. Many hip-fracture patients experience severe functional impairment, and most never recover their pre-fracture level of function. Current research has sought to identify the most effective treatments to reduce the incidence of hip fractures, improve survival and quality of life, and minimize complications and disability. The treatment of these fractures in the elderly aims to return these people to their pre-fracture mobility and functional level. This article reviews the surgical treatment options for extracapsular hip fractures and discusses their associated advantages, disadvantages, and complications. Two types of implants are currently available: the dynamic hip screw (DHS), and the intramedullary hip nail with one or two sliding screws. In this review, no clear advantage of one implant over another for the treatment of extracapsular hip fractures was evident. Both the DHS and hip nails can be used successfully for the treatment of stable hip fractures; for unstable fractures and low subtrochanteric fractures, hip nails are preferred. Although hip nails are associated with limited exposure, lower blood loss and transfusion requirements, and shorter operative time, complications are more common with hip nails. Long-term survival and function are similar in the two approaches. Hip nails with two sliding screws do not seem to make the difference in clinical practice that is reported in biomechanical studies. PMID:23016784

The presence of radomes and instruments that are sensitive to water films or ice formations in the nose section of all-weather aircraft and missiles necessitates a knowledge of the droplet impingement characteristics of bodies of revolution. Because it is possible to approximate many of these bodies with an ellipsoid of revolution, droplet trajectories about an ellipsoid of revolution with a fineness ratio of 5 were computed for incompressible axisymmetric air flow. From the computed droplet trajectories, the following impingement characteristics of the ellipsoid surface were obtained and are presented in terms of dimensionless parameters: (1) total rate of water impingement, (2) extent of droplet impingement zone, (3) distribution of impinging water, and (4) local rate of water impingement.

The presence of radomes and instruments that are sensitive to water films or ice formations in the nose section of all-weather aircraft and missiles necessitates a knowledge of the droplet impingement characteristics of bodies of revolution. Because it is possible to approximate many of these bodies with an ellipsoid of revolution, droplet trajectories about an ellipsoid of revolution with a fineness ratio of 10 were computed for incompressible axisymmetric air flow. From the computed droplet trajectories, the following impingement characteristics of the ellipsoid surface were obtained and are presented in terms of dimensionless parameters: (1) total rate of water impingement, (2) extent of droplet impingement zone, and (3) local rate of water impingement. These impingement characteristics are compared briefly with those previously reported for an ellipsoid of revolution with a fineness ratio of 5.

The advantages of sonographic examination are well known, but its main disadvantage is that it might lead to overdiagnosis, which might cause overtreatment. Variations in the incidence of developmental dysplasia of the hip are well known. We ascertained the incidence of neonatal sonographic developmental dysplasia of the hip without considering the development of those joints during followup. All 45,497 neonates (90,994 hips) born in our institute between January 1992 and December 2001 were examined clinically and sonographically during the first 48 hours of life. Sonography was performed according to Graf’s method, which considers mild hip sonographic abnormalities as Type IIa. We evaluated the different severity type incidence pattern and its influence on the total incidence during and between the investigated years. According to our study, sonographic Type IIa has major effects on the incidence of overall developmental dysplasia of the hip with a correlation coefficient of 0.95, whereas more severe sonographic abnormalities show relatively stable incidence patterns. Level of Evidence: Level I, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence. PMID:18288551

Over the past two decades there has been a heightened interest in implementing gelled propellants for rocket propulsion, especially for hypergolic bi-propellants such as monomethylhydrazine (MMH) and nitrogen tetroxide oxidizer (NTO). Due to the very high level of toxicity of hypergolic liquid rocket propellants, increasing safety is an important area of need for continued space exploration and defense operations. Gelled propellants provide an attractive solution to meeting the requirements for safety, while also potentially improving performance. A gelling agent can be added to liquid propellants exhibiting Newtonian behavior to transform the liquid into a non-Newtonian fluid with some solid-like behavior, i.e. a gel. Non-Newtonian jet impingement is very different from its Newtonian counterpart in terms of fluid flow, atomization, and combustion. This is due to the added agents changing physical properties such as the bulk rheology (viscosity) and interfacial rheology (surface tension). Spray characterization of jet impingement with Newtonian liquids has been studied extensively in existing literature. However, there is a scarcity in literature of studies that consider the spray characterization of jet impingement with gelled propellants. This is a rather critical void since a major tradeoff of utilizing gelled propellants is the difficulty with atomization due to the increased effective viscosity. However, this difficulty can be overcome by using gels that exhibit shear-thinning behavior---viscosity decreases with increasing strain rate. Shear-thinning fluids are ideal because they have the distinct advantage of only flowing easily upon pressure. Thereby, greatly reducing the amount of propellant that could be accidentally leaked during both critical functions such as liftoff or engagement in the battlefield and regular tasks like refilling propellant tanks. This experimental work seeks to help resolve the scarcity in existing literature by providing drop size

Spray cooling has high potential in thermal management and life support systems by overcoming the deleterious effect of microgravity upon two-phase heat transfer. In particular spray cooling offers several advantages in heat flux removal that include the following: 1) By maintaining a wetted surface, spray droplets impinge upon a thin fluid film rather than a dry solid surface; 2. Most heat transfer surfaces will not be smooth but rough. Roughness can enhance conductive cooling, aid liquid removal by flow channeling; and 3. Spray momentum can be used to a) substitute for gravity delivering fluid to the surface, b) prevent local dryout and potential thermal runaway and c) facilitate liquid and vapor removal. Yet high momentum results in high We and Re numbers characterizing the individual spray droplets. Beyond an impingement threshold, droplets splash rather than spread. Heat flux declines and spray cooling efficiency can markedly decrease. Accordingly we are investigating droplet impingement upon a) dry solid surfaces, b) fluid films, c) rough surfaces and determining splashing thresholds and relationships for both dry surfaces and those covered by fluid films. We are presently developing engineering correlations delineating the boundary between splashing and non-splashing regions. Determining the splash/non-splash boundary is important for many practical applications. Coating and cooling processes would each benefit from near-term empirical relations and subsequent models. Such demonstrations can guide theoretical development by providing definitive testing of its predictive capabilities. Thus, empirical relations describing the boundary between splash and non-splash are given for drops impinging upon a dry solid surface and upon a thin fluid film covering a similar surface. Analytical simplification of the power laws describing the boundary between the splash and non-splash regions yields insight into the engineering parameters governing the splash and non

Despite improvements in technique and technology for total knee arthroplasty (TKA), anterior knee pain impacts patient outcomes and satisfaction. Addressing the prosthetic and surgical technique related causes of pain after TKA, specifically as it relates to anterior knee pain, can aid surgeons in addressing these issues with their patients. Design features of the femoral and patellar components which have been reported as pain generators include: Improper femoral as well as patellar component sizing or designs that result in patellofemoral stuffing; a shortened trochlear groove distance from the flange to the intercondylar box; and then surgical technique related issues resulting in: Lateral patellar facet syndrome; overstuffed patella/flange combination; asymmetric patellar resurfacing, improper transverse plane component rotation resulting in patellar subluxation/tilt. Any design consideration that allows impingement of extensor mechanism anatomical elements has the possibility of impacting outcome by becoming a pain generator. As the number of TKA procedures continues to increase, it is increasingly critical to develop improved, evidence based prostheses that maximize function and patient satisfaction while minimizing pain and other complications. PMID:26601061

An injector optimization methodology, method i, is used to investigate optimal design points for a gaseous oxygen/gaseous hydrogen (GO2/GH2) impinging injector element. The unlike impinging element, a fuel-oxidizer- fuel (F-O-F) triplet, is optimized in terms of design variables such as fuel pressure drop, (Delta)P(sub f), oxidizer pressure drop, (Delta)P(sub o), combustor length, L(sub comb), and impingement half-angle, alpha, for a given mixture ratio and chamber pressure. Dependent variables such as energy release efficiency, ERE, wall heat flux, Q(sub w), injector heat flux, Q(sub inj), relative combustor weight, W(sub rel), and relative injector cost, C(sub rel), are calculated and then correlated with the design variables. An empirical design methodology is used to generate these responses for 163 combinations of input variables. Method i is then used to generate response surfaces for each dependent variable. Desirability functions based on dependent variable constraints are created and used to facilitate development of composite response surfaces representing some, or all, of the five dependent variables in terms of the input variables. Three examples illustrating the utility and flexibility of method i are discussed in detail. First, joint response surfaces are constructed by sequentially adding dependent variables. Optimum designs are identified after addition of each variable and the effect each variable has on the design is shown. This stepwise demonstration also highlights the importance of including variables such as weight and cost early in the design process. Secondly, using the composite response surface which includes all five dependent variables, unequal weights are assigned to emphasize certain variables relative to others. Here, method i is used to enable objective trade studies on design issues such as component life and thrust to weight ratio. Finally, specific variable weights are further increased to illustrate the high marginal cost of

Plume impingement effects from the descent and ascent engine firings of the Lunar Lander were analyzed in support of the Lunar Architecture Team under the Constellation Program. The descent stage analysis was performed to obtain shear and pressure forces on the lunar surface as well as velocity and density profiles in the flow field in an effort to understand lunar soil erosion and ejected soil impact damage which was analyzed as part of a separate study. A Computational Fluid Dynamics (CFD)/Direct Simulation Monte Carlo (DSMC) decoupled methodology was used with the Bird continuum breakdown parameter to distinguish the continuum flow from the rarefied flow. The ascent stage analysis was performed to ascertain the forces and moments acting on the Lunar Lander Ascent Module due to the firing of the main engine on take-off. The Reacting and Multiphase Program (RAMP) method of characteristics (MOC) code was used to model the continuum region of the nozzle plume, and the DSMC Analysis Code (DAC) was used to model the impingement results in the rarefied region. The ascent module (AM) was analyzed for various pitch and yaw rotations and for various heights in relation to the descent module (DM). For the ascent stage analysis, the plume inflow boundary was located near the nozzle exit plane in a region where the flow number density was large enough to make the DSMC solution computationally expensive. Therefore, a scaling coefficient was used to make the DSMC solution more computationally manageable. An analysis of the effects of this scaling technique was performed. Because the inflow boundary was near the nozzle exit plane, another analysis was performed investigating three different inflow contours to determine the effects of the flow expansion around the nozzle lip on the final plume impingement results.

Background Heat transfer enhancement technology concerns with the aim of developing more efficient systems to satisfy the increasing demands of many applications in the fields of automotive, aerospace, electronic and process industry. A solution for obtaining efficient cooling systems is represented by the use of confined or unconfined impinging jets. Moreover, the possibility of increasing the thermal performances of the working fluids can be taken into account, and the introduction of nanoparticles in a base fluid can be considered. Results In this article, a numerical investigation on confined impinging slot jet working with a mixture of water and Al2O3 nanoparticles is described. The flow is turbulent and a constant temperature is applied on the impinging. A single-phase model approach has been adopted. Different geometric ratios, particle volume concentrations and Reynolds number have been considered to study the behavior of the system in terms of average and local Nusselt number, convective heat transfer coefficient and required pumping power profiles, temperature fields and stream function contours. Conclusions The dimensionless stream function contours show that the intensity and size of the vortex structures depend on the confining effects, given by H/W ratio, Reynolds number and particle concentrations. Furthermore, for increasing concentrations, nanofluids realize increasing fluid bulk temperature, as a result of the elevated thermal conductivity of mixtures. The local Nusselt number profiles show the highest values at the stagnation point, and the lowest at the end of the heated plate. The average Nusselt number increases for increasing particle concentrations and Reynolds numbers; moreover, the highest values are observed for H/W = 10, and a maximum increase of 18% is detected at a concentration equal to 6%. The required pumping power as well as Reynolds number increases and particle concentrations grow, which is almost 4.8 times greater than the

The present paper addresses an experimental study of the dynamic exchanges between the impact of an intermittent spray and the liquid film formed over the target, based on detailed phase Doppler anemometry (PDA) measurements of droplet size, velocity and volume flux in the vicinity of the impact. The flow configuration is that of a pulsed injector spraying gasoline onto a flat disc to simulate the port fuel injection (PFI) of an internal combustion engine operating at cold-start conditions. The measurements evidence that the outcome of impact cannot be accurately predicted based on the characteristics of the free spray, but requires precise knowledge of the flow structure, induced by the target. The implications for spray wall interaction modelling are then discussed based on the application of conservation equations to the mass, momentum and energy exchanged between the impinging droplets and the liquid film. The results show that the liquid film starts to form in the vicinity of the stagnation region at early stages of injection and a non-negligible proportion of droplets impinging at outer regions splash after interaction with the film. Film disruption is mainly driven by the intermittent axial momentum of impinging droplets, which enhances the vertical oscillations. The radial momentum imparted to the liquid film at the stagnation region is fed back onto secondary droplets emerging later during the injection cycle at outwards locations, where momentum of impacting droplets is much smaller. As a consequence, although the number of splashed droplets is enhanced by normal momentum, their size and ejection velocity depends more on the radial spread induced onto the liquid film and, hence, on the radial momentum at impact. The analysis further shows that existing spray wall interaction models can be improved if the dynamic exchanges between the impacting spray and the liquid film are accounted.

Trajectories were determined for water droplets or other aerosol particles in air flowing through 600 elbows especially designed for two-dimensional potential motion. The elbows were established by selecting as walls of each elbow two streamlines of a flow field produced by a complex potential function that establishes a two-dimensional flow around. a 600 bend. An unlimited number of elbows with slightly different shapes can be established by selecting different pairs of streamlines as walls. Some of these have a pocket on the outside wall. The elbows produced by the complex potential function are suitable for use in aircraft air-inlet ducts and have the following characteristics: (1) The resultant velocity at any point inside the elbow is always greater than zero but never exceeds the velocity at the entrance. (2) The air flow field at the entrance and exit is almost uniform and rectilinear. (3) The elbows are symmetrical with respect to the bisector of the angle of bend. These elbows should have lower pressure losses than bends of constant cross-sectional area. The droplet impingement data derived from the trajectories are presented along with equations so that collection efficiency, area, rate, and distribution of droplet impingement can be determined for any elbow defined by any pair of streamlines within a portion of the flow field established by the complex potential function. Coordinates for some typical streamlines of the flow field and velocity components for several points along these streamlines are presented in tabular form. A comparison of the 600 elbow with previous calculations for a comparable 90 elbow indicated that the impingement characteristics of the two elbows were very similar.

Plume impingement effects from the descent and ascent engine firings of the Lunar Lander were analyzed in support of the Lunar Architecture Team under the Constellation Program. The descent stage analysis was performed to obtain shear and pressure forces on the lunar surface as well as velocity and density profiles in the flow field in an effort to understand lunar soil erosion and ejected soil impact damage which was analyzed as part of a separate study. A CFD/DSMC decoupled methodology was used with the Bird continuum breakdown parameter to distinguish the continuum flow from the rarefied flow. The ascent stage analysis was performed to ascertain the forces and moments acting on the Lunar Lander Ascent Module due to the firing of the main engine on take-off. The Reacting and Multiphase Program (RAMP) method of characteristics (MOC) code was used to model the continuum region of the nozzle plume, and the Direct Simulation Monte Carlo (DSMC) Analysis Code (DAC) was used to model the impingement results in the rarefied region. The ascent module (AM) was analyzed for various pitch and yaw rotations and for various heights in relation to the descent module (DM). For the ascent stage analysis, the plume inflow boundary was located near the nozzle exit plane in a region where the flow number density was large enough to make the DSMC solution computationally expensive. Therefore, a scaling coefficient was used to make the DSMC solution more computationally manageable. An analysis of the effectiveness of this scaling technique was performed by investigating various scaling parameters for a single height and rotation of the AM. Because the inflow boundary was near the nozzle exit plane, another analysis was performed investigating three different inflow contours to determine the effects of the flow expansion around the nozzle lip on the final plume impingement results.

The objective of the experimental study was to visualize the temperature distribution and evaluate heat transfer rate on the impingement surface kept at a constant wall temperature boundary condition for the swirling (SIJ), multi-channel (MCIJ) and conventional impinging jet (CIJ) using liquid crystal technique. The swirling jet assembly consisted of a housing tube and a solid swirl generator insert which had four narrow slots machined on its surface. The swirl angle, {theta}, was set as 0 , 22.5 , 41 , 50 to change the direction and strength of the swirl in the air flow exiting the housing tube. The local Nusselt numbers of the MCIJ ({theta} = 0 ) were generally much higher than those of CIJ and SIJs. As the swirl angle increased, the radial uniformity of the heat transfer was seen compared to MCIJ and SIJ; the best results were for {theta} = 50 and the jet-to-surface distance of H/D = 14. The location of the distance of the maximum heat transfer for the swirl angles of {theta} = 41 and 50 was shifted away from the stagnation point in a radial distance of nearly r/D = 2.5. Increasing Reynolds number for same swirler angle increased the heat transfer rate on the entire surface, and increased saddle shape heat transfer distribution on the surface, but had no significant effect on the position of the individual impingement regions, but increased saddle shape heat transfer distribution on the surface. The lower Reynolds number (Re = 10 000) and the highest H/D = 14 gave much more uniform local and average heat transfer distribution on the surface, but decreased their values on the entire surface. (author)

The conventional procedure in the treatment of vertebral tuberculosis is drainage of the abscess, curettage of the devitalized vertebra and application of an antituberculous chemotherapy regimen. Posterior instrumentation results are encouraging in the prevention or treatment of late kyphosis; however, a second-stage operation is needed. Recently, posterolateral or transpedicular drainage without anterior drainage or posterior instrumentation following anterior drainage in the same session has become the preferred treatment, in order that kyphotic deformity can be avoided. Information on the use of anterior instrumentation along with radical debridement and fusion is scarce. This study reports on the surgical results of 63 patients with Pott's disease who underwent anterior radical debridement with anterior fusion and anterior instrumentation (23 patients with Z-plate and 40 patients with CDH system). Average age at the time of operation was 46.8+/-13.4 years. Average duration of follow-up was 50.9+/-12.9 months. Local kyphosis was measured preoperatively, postoperatively and at the last follow-up visit as the angle between the upper and lower end plates of the collapsed vertebrae. Vertebral collapse, destruction, cold abscess, and canal compromise were assessed on magnetic resonance (MR) images. It was observed that the addition of anterior instrumentation increased the rate of correction of the kyphotic deformity (79.7+/-20.1%), and was effective in maintaining it, with an average loss of 1.1 degrees +/-1.7 degrees. Of the 25 patients (39.7%) with neurological symptoms, 20 (80%) had full and 4 (16%) partial recoveries. There were very few intraoperative and postoperative complications (major vessel complication: 3.2%; secondary non-specific infection: 3.2%). Disease reactivation was not seen with the employment of an aggressive chemotherapy regimen. It was concluded that anterior instrumentation is a safe and effective method in the treatment of tuberculosis

The effects of rotation on impingement cooling of turbine blades were studied experimentally as a specialized facility at M.I.T. A foil heated resistively was cooled by a jet flow on one side and temperature monitored on the other. Rotating the blade limits the heat transfer path to conduction through the support structure and radiation. IR radiometry furnishes the temperature distributions on the chamber wall, permitting the internal heat transfer coefficient to be measured. The heat transfer efficiency has been found to fall as much as 30 percent as rotational speed increases. The conditions observed confirm the significance of rotational effects, particularly with regard to potential early blade failure.

In this article measurements of fluid flow through impingement and film cooling holes for typical turbine blade cooling systems are presented. The purpose of the measurements was to determine hole discharge coefficients over a range of Reynolds numbers from 5,000 to 30,000 and to observe in this range the dependence of discharge coefficient on Reynolds number. The effect of hole geometry, that is, sharp edged inlet or corner radius inlet, on discharge coefficients is also measured. Correlations relating discharge coefficients to Reynolds number, corner radius to hole diameter ratio, and blowing parameter are suggested.

An impingement insert sleeve is provided that is adapted to be disposed in a coolant cavity defined through a stator vane. The insert has a generally open inlet end and first and second diametrically opposed, perforated side walls. A metering plate having at least one opening defined therethrough for coolant flow is mounted to the side walls to generally transverse a longitudinal axis of the insert, and is disposed downstream from said inlet end. The metering plate improves flow distribution while reducing ballooning stresses within the insert and allowing for a more flexible insert attachment.